Yemen: Civil War and Regional Intervention

Yemen: Civil War and Regional Intervention
December 8, 2020March 12, 2021
For over a decade, the Republic of Yemen has been torn apart by multiple armed For over a decade, the Republic of Yemen has been torn apart by multiple armed conflicts to conflicts to
which several internal militant groups and foreign nations are parties. which several internal militant groups and foreign nations are parties. Collectively, these
Jeremy M. Sharp
Collectively, these conflicts have eroded central governance in Yemen, and have conflicts have eroded central governance in Yemen, and have fragmented the nation into various
Specialist in Middle Specialist in Middle
fragmented the nation into various local centers of power. The gradual dissolution of local centers of power. The gradual dissolution of Eastern Affairs Yemen’s territorial integrity has alarmed the Yemen’s territorial integrity has alarmed the
Eastern Affairs
United States and others in the international United States and others in the international community. Policymaker concerns include fears that community. Policymaker concerns include fears that

state failure may empower Yemen-state failure may empower Yemen- based transnational terrorist groups; destabilize vital based transnational terrorist groups; destabilize vital
international shipping lanes near the Bab al Mandab strait (also spelled Bab al Mandeb, Bab el international shipping lanes near the Bab al Mandab strait (also spelled Bab al Mandeb, Bab el

Mendeb); and provide opportunities for Iran to threaten Saudi Arabia’s borders. Mendeb); and provide opportunities for Iran to threaten Saudi Arabia’s borders.
Beyond geo-strategic concerns, the collapse of Yemeni institutions during wartime has exacerbated poor living conditions in Beyond geo-strategic concerns, the collapse of Yemeni institutions during wartime has exacerbated poor living conditions in
what has long been the most impoverished Arab country, leading to what is now considered the world’s worst humanitarian what has long been the most impoverished Arab country, leading to what is now considered the world’s worst humanitarian
crisis. This report provides information on these ongoing and overlapping crises. crisis. This report provides information on these ongoing and overlapping crises.
In 2014, the northern Yemeni-based Ansar Allah/Houthi movement (referred to in this report as “the Houthis”) took over the In 2014, the northern Yemeni-based Ansar Allah/Houthi movement (referred to in this report as “the Houthis”) took over the
capital, Sanaa (also commonly spelled Sana’a), and in early 2015, advanced southward from the capital to Aden on the capital, Sanaa (also commonly spelled Sana’a), and in early 2015, advanced southward from the capital to Aden on the
Arabian Sea. In March 2015, after Yemeni President Abdu Rabbu Mansour Hadi, who had fled to Saudi Arabia, appealed for Arabian Sea. In March 2015, after Yemeni President Abdu Rabbu Mansour Hadi, who had fled to Saudi Arabia, appealed for
international intervention, Saudi Arabia assembled a coalition of several of its Arab partners (referred to in this report as “the international intervention, Saudi Arabia assembled a coalition of several of its Arab partners (referred to in this report as “the
Saudi-led coalition”) and launched a military offensive aimed at restoring Hadi’s rule and dislodging Houthi fighters from the Saudi-led coalition”) and launched a military offensive aimed at restoring Hadi’s rule and dislodging Houthi fighters from the
capital and other major cities. capital and other major cities.
Since then, the conflict in Yemen has killed tens of thousands, caused significant humanitarian suffering, and has Since then, the conflict in Yemen has killed tens of thousands, caused significant humanitarian suffering, and has
significantly damaged the country’s infrastructure. One U.S.- and European-funded organization, the Armed Conflict significantly damaged the country’s infrastructure. One U.S.- and European-funded organization, the Armed Conflict
Location & Event Data Project (ACLED), estimates as of November 2020 that more than 130,000 Yemenis have been killed Location & Event Data Project (ACLED), estimates as of November 2020 that more than 130,000 Yemenis have been killed
since 2015. since 2015.
Although media coverage of the Saudi-led intervention has characterized the war as a binary conflict (the Saudi-led coalition Although media coverage of the Saudi-led intervention has characterized the war as a binary conflict (the Saudi-led coalition
versus the Houthis), there actually have been a multitude of combatants whose alliances and loyalties have been somewhat versus the Houthis), there actually have been a multitude of combatants whose alliances and loyalties have been somewhat
fluid. In summer 2019 in southern Yemen, long-simmering tensions between the internationally recognized Republic of fluid. In summer 2019 in southern Yemen, long-simmering tensions between the internationally recognized Republic of
Yemen government (ROYG) and the separatist Southern Transitional Council (STC) boiled over, leading to open warfare Yemen government (ROYG) and the separatist Southern Transitional Council (STC) boiled over, leading to open warfare
between the local allies of Saudi Arabia and the United Arab Emirates. In 2020, periodic clashes continued, though both sides between the local allies of Saudi Arabia and the United Arab Emirates. In 2020, periodic clashes continued, though both sides
have pledged to share power infinally implemented a power sharing agreement at the end of the year and formed a coalition government. a coalition government.
Many foreign observers have denounced human rights violations that they charge have been committed by all parties to the Many foreign observers have denounced human rights violations that they charge have been committed by all parties to the
conflict. In the United States and some European countries, there has been vociferous opposition to coalition air strikes that conflict. In the United States and some European countries, there has been vociferous opposition to coalition air strikes that
hit civilian targets, leading Congress to debate and enact some legislation to limit U.S. support for the coalition. Some in hit civilian targets, leading Congress to debate and enact some legislation to limit U.S. support for the coalition. Some in
Congress opposed to such efforts have highlighted Iran’s support for the Houthis as a major factor in Yemen’s Congress opposed to such efforts have highlighted Iran’s support for the Houthis as a major factor in Yemen’s
destabilization. The Trump Administration opposes congressional efforts to restrain U.S. support for Saudi Arabia and the
United Arab Emirates and continues to call for a comprehensive settlement to the conflict in line with relevant U.N. Security
Council resolutions and other international initiatives.destabilization.
For several years, Yemen has been considered the worst humanitarian crisis in the world, and public health experts warn that For several years, Yemen has been considered the worst humanitarian crisis in the world, and public health experts warn that
the Coronavirus Disease 2019 (COVID-19) pandemic may have significant negative effects on Yemen’s vulnerable the Coronavirus Disease 2019 (COVID-19) pandemic may have significant negative effects on Yemen’s vulnerable
population. To date, most humanitarian agencies believe that the extent of the outbreak in Yemen has been underreported. population. To date, most humanitarian agencies believe that the extent of the outbreak in Yemen has been underreported.
For additional information on Yemen, including a summary of relevant legislation, please see CRS Report R45046, For additional information on Yemen, including a summary of relevant legislation, please see CRS Report R45046, Congress
and the War in Yemen: Oversight and Legislation 2015-2020, by Jeremy M. Sharp, Christopher M. Blanchard, and Sarah R. , by Jeremy M. Sharp, Christopher M. Blanchard, and Sarah R.
Collins. Collins.

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Yemen: Civil War and Regional Intervention Congressional Research Service link to page 5 link to page 4 link to page 5 link to page link to page 5 link to page 98 link to page link to page 109 link to page link to page 119 link to page link to page 1110 link to page link to page 1311 link to page link to page 1412 link to page link to page 1612 link to page link to page 1812 link to page link to page 2014 link to page link to page 2114 link to page link to page 2215 link to page link to page 237 link to page link to page 58 link to page 9 link to page link to page 9 link to page 1411 link to page link to page 2213 link to page link to page 2416 Yemen: Civil War and Regional Intervention

Contents
Overview ......................................................................................................................................... 1
Recent Developments in Yemen’s Multiple Conflicts Changes in U.S. Policy ............................................................................................... 2
International Peace Efforts.. 1 The Houthi-ROYG War in the North: The Battle for Marib ..................................................... 4 Clashes Continue in Hudaydah ......................................................... 6
The Stockholm Agreement .................................. 5 Failing Oil Tanker ...................................................................... 7
Issues for Congress ......................................... 5 The Houthi-Saudi Arabia Conflict ................................................................................. 8
Possible U.S. Designation of the Houthis as a Foreign Terrorist Organization ........................ 8
Yemen’s Humanitarian Crisis........... 6 Southern Yemen: Tentative Unity between the ROYG and STC .............................................. 7 Iranian Support to the Houthis ................................................................................................. 10
Iranian Support to the Houthis. 8 Yemen’s Humanitarian Crisis ................................................................................................. 11
Saudi-led Coalition Operations in Yemen and Civilian Casualties .. 8 Food Insecurity & Humanitarian Access ............................................................................ 13
U.S. Counterterrorism Operations8 The COVID-19 Pandemic in Yemen ................................................................................ 10 International Pledges for 15
Possible Illegal Transfer of U.S. Weaponry in Yemen ............................................................ 17
U.S. Bilateral Aid to Yemen ........................... 10 Conflict Analysis ........................................................................... 18
Recent Legislation ............................................ 11 Figures Figure 1. Lines of Control in Yemen ....................................................................... 19
Trump Administration Policy and Outlook for the Incoming Administration ............................... 20

Figures 3
Figure 1. Significant Events in Yemen: 2011-20192. Lines of Control in Marib Governorate ......................................................................... 2

Tables
Table 1. Key Groups in Yemen Conflict .. 4 Figure 3. U.N. Monitors in Hudaydah ............................................................................................. 6
Table 2. U.S. Humanitarian Response to the Complex Crisis in Yemen: FY2015-FY2020 ......... 11
Table 3. U.S. Bilateral Aid to Yemen: FY2016-FY2021 Request5 Figure 4. Saudi-led Coalition Air Strikes Per Month ...................................................................... 7 Figure 5. World Food Programme: Emergency Dashboard Yemen ................................................. 199

Contacts
Author Information ........................................................................................................................ 2112

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Overview
For over a decade, the Republic of Yemen1 has been torn apart by multiple armed conflicts to For over a decade, the Republic of Yemen1 has been torn apart by multiple armed conflicts to
which several internal militant groups and foreign nations are parties. Collectively, these conflicts which several internal militant groups and foreign nations are parties. Collectively, these conflicts
have eroded central governance in Yemen, and have fragmented the nation into various local have eroded central governance in Yemen, and have fragmented the nation into various local
centers of power. The gradual dissolution of Yemen’s territorial integrity has alarmed the United centers of power. The gradual dissolution of Yemen’s territorial integrity has alarmed the United
States and others in the international community. Policymaker concerns include fears that state States and others in the international community. Policymaker concerns include fears that state
failure may empower Yemen-based transnational terrorist groups; destabilize vital international failure may empower Yemen-based transnational terrorist groups; destabilize vital international
shipping lanes near the Bab al Mandab strait2 (also spelled Bab al Mandeb, Bab el Mendeb); and shipping lanes near the Bab al Mandab strait2 (also spelled Bab al Mandeb, Bab el Mendeb); and
provide opportunities for Iran to threaten Saudi Arabia’s borders. Beyond geo-strategic concerns, provide opportunities for Iran to threaten Saudi Arabia’s borders. Beyond geo-strategic concerns,
the collapse of Yemeni institutions during wartime has exacerbated poor living conditions in what the collapse of Yemeni institutions during wartime has exacerbated poor living conditions in what
has long been the most impoverished Arab country, leading to what is now considered the world’s has long been the most impoverished Arab country, leading to what is now considered the world’s
worst humanitarian crisis. worst humanitarian crisis.
As of As of December 2020March 2021, Yemen remains beset by multiple armed and political conflicts which, in , Yemen remains beset by multiple armed and political conflicts which, in
their totality, have crippled central governance, devastated the national economy, and exacerbated their totality, have crippled central governance, devastated the national economy, and exacerbated
a longstandinga long-standing humanitarian crisis. One U.S.- and European-funded organization, the Armed humanitarian crisis. One U.S.- and European-funded organization, the Armed
Conflict Location & Event Data Project (ACLED), estimates that from the start of regional Conflict Location & Event Data Project (ACLED), estimates that from the start of regional
intervention in Yemen in March 2015 until November 2020, over 130,000 Yemenis had been intervention in Yemen in March 2015 until November 2020, over 130,000 Yemenis had been
killed in various acts of violence.3 killed in various acts of violence.3
Coronavirus Disease 2019 (COVID-19) Impact on Yemen
Due to the loss of central governance in Yemen, outside observers have had difficulty understanding the extent of
the COVID-19 pandemic in Yemen. To date, most humanitarian agencies believe that the extent of the outbreak
in Yemen has been underreported.4 One group of researchers in the United Kingdom recently used high-
resolution satellite imagery to analyze burial activity at cemeteries in Yemen's southern Aden governorate, where
they determined there had been an estimated 2,100 "excess deaths" between April and September 2020.5Recent Changes in U.S. Policy Since March 2015, Saudi Arabia and members of a coalition it established have been engaged in military operations in Yemen against the Houthi movement, or Ansar Allah, which the U.S. government believes receives some material support from Iran. As of February 2021, the epicenter of fighting was around the northern governorate and city of Marib (see Figure 2), one of the last areas under the control of the internationally-recognized Republic of Yemen Government (ROYG) led by Yemeni President Abdu Rabbu Mansour Hadi.

1 Since its 1990 unification, Yemen has been a republic in which, according to Article 4 of its 2001 constitution (as 1 Since its 1990 unification, Yemen has been a republic in which, according to Article 4 of its 2001 constitution (as
amended), “The people of Yemen are the possessor and the source of power, which they exercise directly through amended), “The people of Yemen are the possessor and the source of power, which they exercise directly through
public referendums and elections, or indirectly through the legislative, executive and judicial authorities, as well as public referendums and elections, or indirectly through the legislative, executive and judicial authorities, as well as
through elected local councils.” In reality, the late President Ali Abdullah Saleh ruled a unified Yemen from 1990-through elected local councils.” In reality, the late President Ali Abdullah Saleh ruled a unified Yemen from 1990-
2012. After popular uprisings swept across the Arab world in 2011, including in Yemen, the Gulf Cooperation Council 2012. After popular uprisings swept across the Arab world in 2011, including in Yemen, the Gulf Cooperation Council
(GCC) helped broker a transition plan for Yemen, which was endorsed by the United Nations (see, U.N. Security (GCC) helped broker a transition plan for Yemen, which was endorsed by the United Nations (see, U.N. Security
Council Resolution 2014) and superseded the authority of Yemen’s constitution. As part of Yemen’s transition from Council Resolution 2014) and superseded the authority of Yemen’s constitution. As part of Yemen’s transition from
the longtime rule of President Saleh to President Hadi, all of Yemen’s various political factions (565 individual the longtime rule of President Saleh to President Hadi, all of Yemen’s various political factions (565 individual
delegates) held what was called the National Dialogue Conference (NDC) from 2013-2014. That conference was delegates) held what was called the National Dialogue Conference (NDC) from 2013-2014. That conference was
intended to settle all of Yemen’s outstanding political issues, including producing recommendations which were to be intended to settle all of Yemen’s outstanding political issues, including producing recommendations which were to be
used by a Constitutional Drafting Committee to create a new constitution, which would then be voted on in a national used by a Constitutional Drafting Committee to create a new constitution, which would then be voted on in a national
referendum. However, in January 2014 the NDC ended without agreement and shortly thereafter, the Houthis launched referendum. However, in January 2014 the NDC ended without agreement and shortly thereafter, the Houthis launched
a military offensive to seize large swaths of northern Yemen, culminating in their capture of the capital Sana’a in a military offensive to seize large swaths of northern Yemen, culminating in their capture of the capital Sana’a in
September 2014. September 2014.
2 After the Straits of Hormuz and Malacca, the Bab al Mandab is one of the world’s busiest chokepoints in terms of 2 After the Straits of Hormuz and Malacca, the Bab al Mandab is one of the world’s busiest chokepoints in terms of
volume of crude oil and petroleum liquids transported through each day. According to the Energy Information volume of crude oil and petroleum liquids transported through each day. According to the Energy Information
Administration, “Total petroleum flows through the Bab el-Mandeb Strait accounted for about 9% of total seaborne-Administration, “Total petroleum flows through the Bab el-Mandeb Strait accounted for about 9% of total seaborne-
traded petroleum (crude oil and refined petroleum products) in 2017.” See, U.S. Energy Information Administration, traded petroleum (crude oil and refined petroleum products) in 2017.” See, U.S. Energy Information Administration,
“The Bab el-Mandeb Strait is a Strategic Route for Oil and Natural Gas Shipments, August 27, 2019. “The Bab el-Mandeb Strait is a Strategic Route for Oil and Natural Gas Shipments, August 27, 2019.
3 The Armed Conflict Location & Event Data Project (ACLED), Dashboard, available online at: 3 The Armed Conflict Location & Event Data Project (ACLED), Dashboard, available online at:
[https://acleddata.com/dashboard/#/dashboard] [https://acleddata.com/dashboard/#/dashboard]
4 United Nations, Yemen Humanitarian Country Team, “Yemen: Preparedness and Response Snapshot Covid-19,” as
of October 24, 2020.
5 “Grave-Counting Satellite Images Seek to Track Yemen's COVID Death Toll,” Reuters, October 29, 2020.
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Figure 1. Significant Events in Yemen: 2011-2019

Source: Created by CRS using open source reporting.
Recent Developments in Yemen’s Multiple Conflicts
The Houthi-ROYG Conflict – Since 2014, the northern Yemeni-based Ansar Allah, commonly
referred to as the Houthi movement (referred to in this report as “the Houthis”) has battled for
power with the internationally recognized Republic of Yemen government (ROYG), which has
been aided militarily by Saudi Arabia and, until its 2019 troop withdrawal, the United Arab
Emirates. As of late 2020, the epicenter of fighting has been around the northern governorate and
city of Marib, one of the last Yemeni areas under the control of the ROYG and where Yemen’s
modest oil and gas reserves are located. The Houthis have been pressing ROYG forces along
three fronts, but Saudi airstrikes have somewhat slowed Houthi advances. Tribal forces aligned
with the ROYG also have stymied the Houthis from seizing Marib city, as several local tribes
have strong ties to Saudi Arabia and have coordinated with Saudi forces to repel the Houthi
offensive.6 The Houthis have suffered several notable casualties, including one Hezbollah-trained
Houthi commander, who was a close confidant of Houthi leader Abdul Malek al Houthi.7





6 Ali Al-Sakani and Casey Coombs, “Marib: A Yemeni Government Stronghold Increasingly Vulnerable to Houthi
Advances,” Sana’a Center for Strategic Studies, October 22, 2020.
7 Ahmed al Haj, “Senior Rebel Commander Killed in Yemen amid Fierce Battles,” Associated Press, May 7, 2020.
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Who are the Houthis?
The Houthi movement (formally known as Ansar Allah or Partisans of God) is a predominantly Zaydi Shia revivalist
political and insurgent movement. Yemen’s Zaydis take their name from their fifth Imam, Zayd ibn Ali, grandson of
Husayn, son of Ali (the cousin and son-in-law of the prophet Muhammad). Zayd revolted against the Umayyad
Caliphate in 740 C.E., believing it to be corrupt, and to this day, Zaydis believe that their imam (ruler of the
community) should be both a descendent of Ali and one who makes it his religious duty to rebel against unjust
rulers and corruption. A Zaydi state (or Imamate) was founded in northern Yemen in 893 C.E. and lasted in
various forms until the republican revolution of 1962. Yemen’s modern imams kept their state in the Yemeni
highlands in extreme isolation, requiring foreign visitors to obtain the ruler’s permission to enter the kingdom.
Although Zaydism is an offshoot of Shia Islam, it is doctrinally distinct from “Twelver Shi sm,” the dominant branch
of Shia Islam in Iran and Lebanon. Zaydism’s legal traditions and religious practices are more similar to Sunni Islam.
The Houthi movement was formed in the northern Yemeni governorate of Sa’dah (in the mountainous district of
Marran) in 2004 under the leadership of members of the Houthi family. Between 2004 and 2010, the central
government and the Houthis fought six wars in northern Yemen. With each successive round of fighting, the
Houthis improved their position, as anti-government sentiment became more widespread amidst an aggrieved
population in a war-torn and neglected north. Although the Houthi movement originally sought an end to what it
viewed as Saudi-backed efforts to marginalize Zaydi communities and beliefs,8 its goals grew in scope and ambition
in the wake of the 2011 uprising and government col apse to embrace a broader populist, anti-establishment
message. Ideological y, the group has espoused anti-American and anti-Zionist beliefs, embodied by the slogans
prominently displayed on its banners: “God is great! Death to America! Death to Israel! Curse the Jews! Victory
to Islam!”
For Saudi Arabia, according to one prominent analyst, the Houthis embody what Iran seeks to achieve across the
Arab world: that is, the cultivation of an armed non-state, non-Sunni actor who can pressure Iran’s adversaries
both politically and militarily (akin to Hezbol ah in Lebanon).9 A decade before the current conflict began in 2015,
Saudi Arabia supported the central government of Yemen in various military campaigns against a Houthi
insurgency.10
The Houthi-Saudi Conflict – Since a Saudi-led coalition intervened on behalf of the ROYG in
2015, the Houthis and coalition forces have been engaged in what is referred to informally as an
air or missile war, in which the Saudis have conducted numerous air strikes in northern Yemen,
while the Houthis have launched ballistic missiles and unmanned aerial vehicles (UAVs) into
Saudi territory. As of mid-2020, reports of errant Saudi air strikes that have resulted in civilian
casualties continue.11 The Yemen Data Project, a non-profit independent data collection project
that disseminates data on the conduct of the war in Yemen, has tallied over 21,000 Saudi-led
coalition air strikes since March 2015, resulting in over 18,500 civilian casualties.12
While the Houthis do not possess manned aircraft, they have conducted persistent ballistic missile
and UAV launches against Saudi territory in an ongoing campaign they claim is in response to the
Saudi-led coalition’s ongoing maritime blockade of Yemen’s west coast and closure of Sana’a

8 See J.E. Peterson, Arabian Peninsula Background Notes APBN-006, “The al-Huthi Conflict in Yemen,” published on
http://www.JEPeterson.net, August 2008.
9 Bruce Riedel, “Who are the Houthis, and Why are we at War with them?” Brookings, MARKAZ, December 18,
2017.
10 During the Cold War, Saudi Arabia’s leaders supported northern Yemeni Zaydis as a bulwark against nationalist and
leftist rivals, and engaged in proxy war against Egypt-backed Yemeni nationalists during the 1960s. The revolutionary,
anti-Saudi ideology of the Houthi movement, which emerged in the 1990s, presented new challenges. In 2009, Saudi
Arabia launched a three-month air and ground campaign in support of the Yemeni government’s Operation Scorched
Earth. Saudi Arabia dispatched troops along the border of its southernmost province in an attempt to repel reported
Houthi infiltration of Saudi territory. It is estimated that Saudi Arabia lost 133 soldiers in its war against the Houthis.
Saudi Arabia agreed to a cease-fire with the Houthis in late February 2010 after an exchange of prisoners.
11 Ahmed al Haj, “UN: Up to 9 Children Killed by Airstrikes in Northern Yemen,” Associated Press, August 7, 2020.
12 Yemen Data Project, Air War Dataset, available online at: [https://yemendataproject.org/data.html]
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airport. While Houthi attacks occur regularly, there have been at least five occasions in which the
Houthis have used longer-range weapons to target sensitive Saudi defense and energy
infrastructure.13 In June 2020, the Houthis launched ballistic missiles and UAVs targeting the
Saudi Ministry of Defense and King Salman Air Base, though the extent of any significant
damage is unknown.14 In November 2020, the Houthis fired cruise missiles into Saudi territory
and damaged a Saudi Aramco oil distribution station in Jeddah, a major port located on Saudi
Arabia’s western coast, a day after the conclusion of a Saudi government-hosted virtual G20
leaders summit.
The STC-ROYG Dispute in South Yemen - In summer 2019, the United Arab Emirates (UAE),
facing a perceived threat from Iran and international criticism of its conduct in Yemen,
unilaterally withdrew most of its forces from Yemen. The UAE had been Saudi Arabia’s primary
partner in the coalition’s war against the Houthis. The UAE’s local partners in southern Yemen,
the Southern Transitional Council (STC), attempted to seize more power in Aden from the Saudi-
backed ROYG following the UAE’s withdrawal. Violent confrontations ensued between STC and
ROYG forces. Although Saudi Arabia and the UAE brokered a power-sharing agreement between
the ROYG and the STC in November 2019 (known as the Riyadh Agreement), implementation of
that deal stalled, leaving the STC ensconced in the south, the Houthis controlling the north, and
the ROYG isolated.
In late April 2020, after damaging flash flooding throughout southern Yemen, the STC declared a
state of emergency and “self-rule” throughout the south in violation of the Riyadh Agreement.
The STC then seized ROYG facilities and hard currency belonging to the Central Bank in Aden.15
Though not all southern Yemeni cities recognized the STC’s declaration of autonomy, the move
alarmed Saudi Arabian and Emirati officials who immediately attempted to bring the STC and
ROYG back to the negotiating table.
In late July 2020, the STC announced that it had renounced “self-rule” and would return to the
power-sharing parameters originally laid out in the Riyadh Agreement. President Hadi then
appointed STC officials as the new governor and security chief of Aden. The STC and ROYG
agreed that the 24 cabinet positions within a new power sharing government would be divided
equally between northern and southern Yemeni leaders. Saudi Arabia also deployed observers to
Aden to verify that STC and ROYG troops had been redeployed to positions outside Aden.16

13 Jessica Kocan, “September 2020 Map Update: Al Houthi ‘Balanced Deterrence’ Campaign,” Critical Threats,
American Enterprise Institute, September 23, 2020.
14 Sudarsan Raghavan and Sarah Dadouch, “Yemeni Rebels Announce Missile and Drone Strikes on Saudi Capital,”
Washington Post, June 23, 2020.
15 Yemen currently has two central banks: one in the Houthi-controlled capital of Sana’a and the other run by the
ROYG in Aden. In 2019-2020, the Houthis banned the circulation of new banknotes issued by the ROYG in Aden
thereby creating a situation in which one nation has two competing currencies. Yemenis seeking to move money
around the country now have to pay change fees, further straining household budgets.
16 “Yemen's Riyadh Agreement: An Overview,” Al Jazeera, July 29, 2020.
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Figure 2. Lines of Control in Yemen
As of October 2020

Source: Graphic created by CRS using data from Risk Intelligence (2020); Esri (2017 & 2018); NOAA (2018);
USGS (2018); Department of State (2015).






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Table 1. Key Groups in Yemen Conflict
Republic of Yemen Government (ROYG)
The internationally recognized government has been led by Abdu Rabbu Mansour Hadi since
2012, when he was elected as caretaker president to replace President Ali Abdul ah Saleh, who
had been in power for 33 years. The Hadi government has been backed by the Saudi-led
coalition since 2015.
Houthi Forces
The Houthi movement (formally known as Ansar Allah or Partisans of God) is a predominantly
Zaydi Shia revivalist political and insurgent movement formed in the northern Yemeni
governorate of Sa'dah under the leadership of members of the Houthi family. The group was

allied with former President Ali Abdul ah Saleh until 2017.
Al Qaeda in the Arabian Peninsula (AQAP)
AQAP has operated in Yemen since 2009 as a successor to previously active AQ members in
the country, and has been most active in Yemen’s southern governorates. AQAP enjoys support

from some inland tribes and has taken and held territory along Yemen's southern coast with
varying degrees of success. AQAP has attempted to carry out attacks in the United States and
Europe.
Southern Transitional Council (STC)
A southern separatist force backed by the United Arab Emirates since the spring of 2017, the
STC is led by Yemeni General Aidarous al Zubaidi, former governor of Aden. The STC and
Hadi government have been at odds over the inclusion of Yemen's main Sunni Islamist party (Al
Islah) in Hadi's government. In August 2019, the STC temporarily took control of Aden,
Yemen’s interim capital.
Source: Prepared by CRS.
International Peace Efforts
As of December 2020, Special Envoy of the United Nations Secretary-General for Yemen Martin
Griffiths continues his efforts to broker a nation-wide cease fire between the Houthis and the
ROYG that would ultimately lead to talks over a political settlement to Yemen’s multitude of
regional and national conflicts.17 Perhaps the biggest obstacle to resolving the Houthi-ROYG
conflict is that the Houthis seek international recognition of their de-facto authority in northern
Yemen, an act of legitimacy that neither the ROYG nor the Saudi government appear ready to
bestow. The ROYG, on the other hand, remains committed to implementing the terms of United
Nations Security Council Resolution (UNSCR) 2216 of 2015, which, among other things,
demanded that the Houthis withdraw from all areas seized during the current conflict.18 This
impasse has been made all the more difficult by the ROYG’s gradual loss of authority both in

17 According to the International Crisis Group, peace talks convened in Kuwait in 2016 were the closest all sides have
come to ending major conflict. Reportedly, the contours of a peace agreement discussed in Kuwait included a series of
steps, such as: (1) ROYG- Houthi cease-fire; (2) the creation of a UN-chaired body to oversee interim security
measures; (3) the formation of a national unity government comprised of both Houthi and ROYG representatives to
rule during a transition period; and (4) national elections to form a permanent government. Parliamentary elections in
Yemen were last held in 2003. See, International Crisis Group, “Rethinking Peace in Yemen,” Report 216, Middle East
and North Africa, July 2, 2020.
18 On April 14, 2015, the United Nations Security Council adopted Resolution 2216, which imposed sanctions on
individuals undermining the stability of Yemen and authorized an arms embargo against the Houthi-Saleh forces. It
also demanded that the Houthis withdraw from all areas seized during the current conflict, relinquish arms seized from
military and security institutions, cease all actions falling exclusively within the authority of the legitimate Government
of Yemen, and fully implement previous council resolutions.
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northern and southern Yemen.19 In practical terms, neither side has agreed to a nation-wide cease
fire, as talks have stalled over Houthi demands that: (1) Sana’a airport be fully reopened; (2) the
ROYG allow civil servants in Houthi-controlled areas to receive salary payments from the
Central Bank in Aden; and (3) the Saudi-led coalition permit imports into the Houthi-controlled
ports of Hudaydah and Saleef.20
In November 2020, Reuters reported that in back channel talks between Saudi Arabia and the
Houthis, Saudi officials indicated that they would be willing to sign a cease-fire and end their air
and sea blockade of Yemen in exchange for the creation of a “buffer zone” where Houthi forces
“leave a corridor along the Saudi borders to prevent incursions and artillery fire.”21
The Stockholm Agreement
In December 2018, Special Envoy Griffiths brokered a cease-fire, known as the Stockholm
Agreement, centered on the besieged Red Sea ort city of Hudaydah (also spelled Hodeidah, Al
Hudaydah). Nearly two years later, the agreement remains unfulfilled and, in fall 2020, Houthi-
ROYG clashes in Hudaydah governorate killed dozens of civilians. On October 8, 2020, Special
Envoy Griffiths released a statement saying, “This military escalation not only constitutes a
violation of the Hudaydah ceasefire agreement but it runs against the spirit of the ongoing UN-
facilitated negotiations that aim to achieve a nationwide ceasefire, humanitarian and economic
measures and the resumption of the political process.”22
The Stockholm Agreement consists of three components: (1) a cease-fire around the port city of
Hudaydah, (2) a 15,000-person prisoner swap, and (3) a statement of understanding that all sides
would form a committee to discuss the war-torn city Taiz. The United Nations agreed to chair a
Redeployment Coordination Committee (RCC) to monitor the cease-fire and redeployment. On
January 16, the United Nations Security Council passed UNSCR 2452, which authorized the
creation of the United Nations Mission to support the Hudaydah Agreement (UNMHA), of which
the RCC was a significant component. It has since been reauthorized until July 2021.
Failing Oil Tanker and Possible Environmental Fallout
Moored off of Yemen’s west coast north of Hudaydah (Houthi-control ed territory)Yemen: Civil War and Regional Intervention As of March 2021, Special Envoy of the United Nations Secretary-General for Yemen Martin Griffiths continues his efforts to broker a nation-wide cease-fire that would ultimately lead to talks over a political settlement to Yemen’s regional and national conflicts. In recent weeks, Griffiths has intensified his diplomatic outreach, traveling to various Gulf Arab states and Iran. Perhaps the biggest obstacle to resolving the war is that the Houthis seek international recognition of their de-facto authority in northern Yemen, a recognition of their legitimacy that neither President Hadi nor the Saudi government appear ready to bestow. On January 19, 2021, the Trump Administration designated the Houthis as a Foreign Terrorist Organization (FTO) and a Specially Designated Global Terrorist (SDGT) entity. In notifying Congress, then-Secretary of State Michael Pompeo identified that the Houthis were closely linked to Iran and that the designations were intended to hold the Houthis accountable for terrorist acts.4 The designations reportedly had been under consideration for months, though aid organizations repeatedly cautioned that designations would exacerbate what the United Nations presently considers the world’s worst humanitarian crisis. On February 11, 2021, Secretary of State Antony Blinken revoked the FTO and SDGT designations of the Houthis. The Secretary retained the designations of five Houthi individuals as Specially Designated Nationals (SDN) under Executive Order (E.O.) 13611. President Obama issued that order in 2012 to block property of persons threatening the peace, security, or stability of Yemen. On March 2, the Biden Administration designated two additional Houthi leaders under E.O 13611.5 4 U.S. Department of State, “Terrorist Designation of Ansarallah in Yemen,” Press Statement, Michael R. Pompeo, Secretary of State, January 10, 2021. 5 U.S. Department of the Treasury, Office of Public Affairs, “Treasury Sanctions Key Military Leaders of the Ansarallah Militia in Yemen,” Press Release, March 2, 2021. Congressional Research Service 2 Yemen: Civil War and Regional Intervention Figure 1. Lines of Control in Yemen As of October 2020 Source: Graphic created by CRS using data from Risk Intelligence (2020); Esri (2017 & 2018); NOAA (2018); USGS (2018); Department of State (2015). Since March 2015, the U.S. military has supported Saudi-led coalition military operations in Yemen, which have come under increasing scrutiny in Congress. However, on February 4, 2021, President Biden announced that his Administration would increase U.S. efforts to resolve the conflict in Yemen by: (1) appointing a special envoy to Yemen; (2) ending U.S. support for offensive operations in the war, including relevant arms sales; and (3) continuing to help Saudi Arabia defend its territory from Houthi attacks. According to one recent report, newly appointed U.S. Special Envoy to Yemen Timothy Lenderking met with Houthi officials in Muscat, Oman, in late February in order to press them to halt their military offensive in Marib (see below) and engage Saudi Arabia in ceasefire negotiations.6 6 “U.S. Officials have Met Yemen's Houthis as Washington Seeks End to War: Sources,” Reuters, March 3, 2021. Congressional Research Service 3 Yemen: Civil War and Regional Intervention Figure 2. Lines of Control in Marib Governorate Source: ACAPS, Yemen: Marib District Profiles, Thematic Report, February 19, 2021 The Houthi-ROYG War in the North: The Battle for Marib As of early March 2021, Houthi forces continue to launch attacks against the forces of the Republic of Yemen Government (ROYG) in Marib governorate. The Marib governorate is the last northern stronghold of the ROYG. An estimated 800,000 internally displaced persons (IDPs), who have fled conflict in other parts of the country, are located there.7 Marib also is the center of Yemen’s modest hydrocarbon sector and, while the country imports over 90% of its oil and gas, the oil refinery in Marib accounts for nearly 8% of Yemen’s total energy needs.8 The Houthis began offensive operations in Marib over a year ago. They escalated their attacks in mid-February, perhaps in an effort to maximize their territorial gains in anticipation of renewed international efforts, including by the Biden Administration, to broker a cease-fire to the conflict. The Houthis may also be trying to consolidate their control over northern Yemen after the recent implementation of the 2019 Riyadh Agreement, which brought the Southern Transition Council (STC), a United Arab Emirates-backed southern Yemeni independence movement, into a unity government with the ROYG. Though it is unlikely that the STC would commit fighters to defend Marib, the Houthis may be pressing ahead now while the balance of power in northern Yemen is 7 United Nations Human Rights, Office of the High Commissioner, “Press briefing notes on Yemen,” February 19, 2021. 8 International Crisis Group, “Crisis in Marib: Averting a Chain Reaction in Yemen,” February 22, 2021. Congressional Research Service 4 Yemen: Civil War and Regional Intervention still in their favor. According to the International Organization for Migration, since January 2020, 140,000 Yemenis have fled from areas close to the frontlines in Marib and other governorates.9 Reports indicate that the Houthis have taken heavy casualties, as the front line remains approximately 10-15 miles outside of Marib city (see Figure 2). While the Houthis have advanced toward Marib city, military analysts suggest that their progress has been slowed. Saudi Arabia continues to support ROYG ground forces with targeted air strikes. The terrain of Marib city itself is relatively flat, which may further expose the Houthi ranks and make it more challenging for their fighters, who are accustomed to fighting on mountainous terrain.10 Clashes Continue in Hudaydah In December 2018, Special Envoy Griffiths brokered a cease-fire, known as the Stockholm Agreement, centered on the besieged Red Sea port city of Hudaydah (also spelled Hodeidah, Al Hudaydah, see Figure 1). More than two years later, the agreement remains unfulfilled and, as of early March 2021, Houthi-ROYG clashes in Hudaydah continue. On March 1, the United Nations Mission to Support the Hudaydah Agreement (UNMHA) condemned a mortar attack in the city that killed five civilians. The United Nations did not attribute blame to a specific group and called on the Houthis and the ROYG to abide by the terms of the ceasefire, prevent civilian casualties, and allow U.N. monitors freedom of movement.11 Currently, the Houthis control the port and city of Hudaydah itself, along with access to Figure 3. U.N. Monitors in Hudaydah the city from the north. To the south along the Red Sea coast, a coalition of forces (dubbed the “Joint Resistance Forces”) led by Tareq Saleh, the nephew of the late former Yemeni President Ali Abdullah Saleh, have remain ensconced since 2018, when the Saudi-led coalition attempted to seize Hudaydah from the Houthis before the Stockholm Agreement halted the fighting. Tareq Saleh’s forces are based out of the port town of Mokha and receive support from Saudi Arabia and the United Arab Emirates. They are not formally part of the ROYG and operate independently from President Hadi. Source: Twitter, U.N. Mission to support the Hudaydah Agreement, October 15, 2020. Failing Oil Tanker Moored off of Yemen’s west coast north of Hudaydah, the 44-year-old floating , the 44-year-old floating
storage and offloading (FSO) storage and offloading (FSO) terminalVessel Safer (owned by the state-run Yemen Oil and Gas Corporation) has been Safer (owned by the state-run Yemen Oil and Gas Corporation) has been
deteriorating for years. It holds an estimated 1.4 deteriorating for years. It holds an estimated 1.4 mil ionmillion barrels of crude oil. Routine maintenance on the tanker barrels of crude oil. Routine maintenance on the tanker
stopped after the Saudi-led intervention began in March 2015. If the FSO Safer were to critically fail, it would stopped after the Saudi-led intervention began in March 2015. If the FSO Safer were to critically fail, it would not
onlylikely cause cause serious environmental damage environmental damage towithin the Red Sea, but would 9 IOM Yemen, “Displacement in Marib,” Flash Update, February 23, 2021. 10 Michael Horton, “Yemen’s Fate Hinges on The Battle for Marib,” The Jamestown Foundation, Terrorism Monitor, Volume: 19 Issue: 4, February 26, 2021. 11 “Yemen: U.N. Ceasefire Monitoring Mission Condemns Attack on Civilians in Hudaydah,” U.N. News, March 1, 2021. Congressional Research Service 5 Yemen: Civil War and Regional Intervention possibly put supplies of drinking water in danger due to its proximity to desalination plants. It could also force the port of Hudaydah to close for months, adding delay to the supply of humanitarian aid to north Yemen. In order to assess the danger, the United Nations had been negotiating with the Houthis to permit a technical team access to the tanker. Although the Houthis had indicated that they would issue entry permits to U.N. inspectors, they have not given their final authorization. One U.N. spokesperson said that while the U.N. has committed $3.3 million to begin work on the Safer, the Houthis may be reconsidering allowing them access.12 The Houthi-Saudi Arabia Conflict Since a Saudi-led coalition intervened on behalf of the ROYG in 2015, the Houthis and coalition forces have been engaged in what is referred to informally as an air or missile war. The Saudis have conducted numerous air strikes in northern Yemen, while the Houthis have launched ballistic missiles and unmanned aerial vehicles (UAVs) into Saudi territory. As of early March 2021, reports of errant Saudi air strikes that have resulted in civilian casualties continue, though far less frequently than in earlier periods of the war (see Figure 4). The Yemen Data Project, a non-profit independent data collection project, has tallied over 22,700 Saudi-led coalition air strikes since March 2015, resulting in over 18,500 civilian casualties.13 Another monitoring organization, The Civilian Impact Monitoring Project (CIMP), a service under the United Nations Protection Cluster for Yemen, recorded 2,087 civilian casualties in 2020 (749 people killed and 1,338 injured), a decrease from 3,224 civilian casualties in 2019 (1,104 deaths and 2,120 injuries), and from 4,934 in 2018 (2,049 deaths and 2,885 injuries).14 While the Houthis do not possess manned aircraft, they have conducted persistent ballistic missile and UAV launches against Saudi territory in an ongoing campaign they claim is in response to the Saudi-led coalition’s ongoing maritime blockade of Yemen’s west coast and closure of Sana'a airport. In February 2021, a Houthi drone attack against Abha Airport in southern Saudi Arabia struck a civilian plane, though no casualties were reported. Secretary of State Blinken condemned the attack.15 In addition to aerial bombardment, the Houthis also have targeted vessels transiting the Red Sea or berthed in Saudi ports.16 12 Rick Gladstone, “U.N. Delays Salvage of Yemen Oil Tanker Amid Fears of Major Spill,” New York Times, February 2, 2021. 13 Yemen Data Project, Air War Dataset, available online at https://yemendataproject.org/data.html. 14 United Nations Office for the Coordination of Humanitarian Affairs, “Yemen Humanitarian Update, Issue 1, January 2021,” February 12, 2021. 15 U.S. Department of State, Office of the Spokesperson, “Secretary Blinken’s Call with Saudi Foreign Minister Faisal bin Farhan Al Saud,” Readout, February 10, 2021. 16 “FACTBOX-Attacks, Incidents on Ships and Oil Around Saudi Arabia,” Reuters, December 14, 2020. Congressional Research Service 6 Yemen: Civil War and Regional Intervention Figure 4. Saudi-led Coalition Air Strikes Per Month Source: Yemen Data Project, February 2021 Southern Yemen: Tentative Unity between the ROYG and STC In December 2020, the UAE-backed Southern Transitional Council (STC) formally joined a unity government with the ROYG, ending several years of clashes in Aden between southern separatists and forces loyal to President Hadi. Saudi Arabia brokered the formation of the unity government after over a year of STC-ROYG negotiations that followed the two sides’ commitment to cooperate as part of the November 2019 Riyadh Agreement. Under their unity arrangement, the STC received several cabinet positions and agreed to redeploy their military forces from Abyan and Aden. On December 30, 2020, as the new members of the government landed at Aden airport to assume their posts, the Houthis launched a coordinated missile attack against the airport, which killed 25 people, including three members of the International Red Cross.17 While the UAE formally withdrew its main military contingent from Yemen in 2019, it has retained a small military presence while working with proxies throughout southern Yemen, most notably the STC. According to the United Nations Panel of Experts on Yemen, “The United Arab Emirates is a member of the Coalition to Restore Legitimacy in Yemen, yet its support to the Southern Transitional Council undermines the Government of Yemen.”18 17 International Committee of the Red Cross, “Yemen: Three ICRC Staff Members Killed in Airport Blast,” December 30, 2020. 18 See United Nations Panel of Experts on Yemen, “Letter dated 22 January 2021 from the Panel of Experts on Yemen addressed to the President of the Security Council,” S/2021/79, January 25, 2021. Congressional Research Service 7 Yemen: Civil War and Regional Intervention Iranian Support to the Houthis Iranian knowledge transfer and military aid to the Houthis, in violation of the targeted international arms embargo ( the Red Sea, but would possibly put supplies of drinking water in
danger due to its proximity to desalination plants. It would also force the port of Hudaydah to close for months,
further delaying the supply of humanitarian aid to north Yemen. In order to assess the long term damage, the
United Nations had been negotiating with the Houthis to permit a technical team access to the tanker. The
Houthis have issued entry permits to UN inspectors and recently gave final inspection approval.
The RCC has not convened since March 2020, when the ROYG suspended its participation in the
body after a Houthi sniper killed a government liaison officer. Many international personnel in
UNMHA have returned to their home countries due to the COVID-19 pandemic. However, in late

19 Op. cit., International Crisis Group.
20 What’s in Blue, “Yemen: Briefing and Consultations,” September 14, 2020.
21 Aziz El Yaakoubi, “Saudis Seek Buffer Zone with Yemen in Return for Ceasefire – Sources,” Reuters, November
17, 2020.
22 United Nations, Office of the Special Envoy of the Secretary-General for Yemen, “Statement by the UN Special
Envoy on Hudaydah,” October 8, 2020.
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September 2020, U.N. mediators facilitated a prisoner swap in an effort to implement part of the
Stockholm Agreement. Under the auspices of the International Committee of the Red Cross, the
Houthis and ROYG agreed to exchange 1,081 prisoners, including 15 Saudis.23
Issues for Congress
Possible U.S. Designation of the Houthis as a Foreign Terrorist
Organization
According to press reports, the Trump Administration is considering designating either specific
Houthi leaders as Specially Designated Global Terrorists (SDGTs)24 or the entire Houthi
organization as a Foreign Terrorist Organization (FTO).25 Since 2018, Trump Administration
officials have considered designating the Houthis, but held off due to concerns from humanitarian
organizations, which claimed that such a policy change would complicate their efforts to deliver
aid in Houthi-controlled areas of northern Yemen.26 However, observers argue that after the
Administration’s 2019 FTO designation of Iran’s Islamic Revolutionary Guard Corps (IRGC),27
the Administration renewed its efforts to also designate the Houthis, though it has not done so as
of December 2020. The U.S. State Department’s 2019 Country Reports on Terrorism notes that:
UN and other reporting have highlighted the connection between the IRGC-QF and the
Houthis, including the provision of lethal aid used by the Houthis to target civilian sites in
Saudi Arabia and the UAE. Media reports suggest that other FTOs, such as Hizballah, may
also be supporting the Houthi militants.28
The United States, United Nations, and international human rights organizations have long
highlighted various Houthi violations of international norms, such as denying humanitarian
access (see below), hostage taking, and persecuting religious minorities.29 Amid charges of
human rights violations by other Yemeni and regional actors, more recent charges against the
Houthis include:
 Targeting Civilian Infrastructure – The most recent U.N. Human Rights
Council annual report on the situation in Yemen notes several instances of
indiscriminate Houthi shelling of civilian infrastructure and laying of land
mines.30

23 Stephanie Nebehay, “Yemen's Warring Parties agree to their Largest Prisoner Swap as U.N. seeks Ceasefire,”
Reuters, September 27, 2020.
24 For background, see CRS In Focus IF10613, Foreign Terrorist Organization (FTO), by John W. Rollins.
25 Colum Lynch, Robbie Gramer, Jack Detsch, “Trump Administration Plans to Designate Yemen’s Houthis as
Terrorists,” Foreignpolicy.com, November 16, 2020.
26 Missy Ryan, John Hudson and Ellen Nakashima, “U.S. Launches new Terrorism Review of Iran-backed Rebels in
Yemen,” Washington Post, September 26, 2020.
27 See CRS Insight IN11093, Iran’s Revolutionary Guard Named a Terrorist Organization, by Kenneth Katzman.
28 U.S. State Department, Country Reports on Terrorism 2019: Yemen, Bureau Of Counterterrorism.
29 For example, see Human Rights Watch, “Yemen Keeps Religious Minority Members Locked Up,” May 28, 2020
and Human Rights Watch, “Yemen: Houthi Hostage-Taking,” September 25, 2018.
30 United Nations Human Rights Council, “Situation of Human Rights in Yemen, including Violations and Abuses
since September 2014,” Report of the Group of Eminent International and Regional Experts on Yemen, September 28,
2020.
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 Detention of Women – According to one April 2020 report, the Houthis have
arrested, imprisoned, and possibly tortured women who oppose their rule.31
 Arrest of Journalists – According to Human Rights Watch, Houthi authorities
have arbitrarily detained journalists and sentenced several to death on politically
motivated charges of treason and spying for foreign states.32
Previous U.S. Sanctions on Houthi Leaders
In May 2012, as the United States sought to support international efforts to dissuade former longtime Yemeni
President Ali Abdul ah Saleh from obstructing the nascent presidency of Abdu Rabbu Mansour Hadi, President
Obama issued Executive Order (EO) 13611,33 which enabled him to sanction individuals who threatened “Yemen’s
peace, security, or stability.” Two and a half years later in November 2014, as Saleh and his new Houthi allies
posed a threat to Hadi’s government, the Treasury Department, pursuant to EO 13611, sanctioned Saleh and two
Houthi military commanders (Abdul ah Yahya al Hakim and Abd al Khaliq al Houthi), thereby freezing their assets
located in the United States or in the control of U.S. persons, and prohibiting U.S. persons from engaging in
transactions with them.34 According to the Treasury Department, “These three individuals have, using violence
and other means, undermined the political process in Yemen.” At the same time, the United Nations also
sanctioned these three individuals pursuant to UNSCR 2140 (asset freeze and travel ban). In April 2015, the
Treasury Department sanctioned the leader of the Houthis, Abdul Malik al-Houthi, and Saleh’s son, Ahmed Ali
Saleh, pursuant to Executive Order (E.O.) 13611.35
Although the Houthis have engaged in anti-American rhetoric36 and have even held several
Americans hostage,37 there is no publicly available accounting of known acts of terrorism against
the United States. In October 2016, military units allied with the Houthi movement and former
Yemeni President Ali Abdullah Saleh (Houthi-Saleh forces) launched anti-ship missiles at U.S.
Navy vessels on patrol off the coast of Yemen. While no U.S. warship was damaged, a similar
attack earlier that month damaged a U.S. transport ship leased by the United Arab Emirates
(UAE). The attacks against the U.S. ships marked the first time U.S. forces had come under direct
fire since the start of the Saudi-led intervention in March 2015. The Obama Administration
responded to the attacks against U.S. naval vessels by firing cruise missiles against Houthi-Saleh
radar installations. The Administration claimed that those attacks were conducted in self-
defense.38
On November 23, 2020, several Senators issued a statement that objected to the possible
designation of the Houthis as an FTO. According to the Senators, “We have reason to believe that
this designation would further destabilize the country, which is already the home of Al Qaeda in
the Arabian Peninsula, make it harder to negotiate a peace agreement, and stop the important

31 Isabel Debre, “Women who Dare Dissent Targeted for Abuse by Yemen’s Rebels,” Associated Press, April 29, 2020.
32 Human Rights Watch, “Yemen: Jailed Journalists Face Abuse, Death Penalty,” November 6, 2020.
33 Pursuant to, inter alia, the International Emergency Economic Powers Act (50 U.S.C. §§ 1701 et seq.) and the
National Emergencies Act (50 U.S.C. §§ 1601 et seq).
34 U.S. Department of the Treasury, “Treasury Sanctions Political Spoilers Threatening the Peace, Security and
Stability of Yemen,” November 10, 2014.
35 U.S. Department of the Treasury, “Treasury Sanctions Instigators of the Violent Takeover of Yemen,” April 14,
2015.
36 For example, see Counter Extremism Project, Houthis. Available online at:
[https://www.counterextremism.com/threat/houthis]
37 Michael Crowley and Adam Goldman, “Houthi Rebels Free 2 American Hostages,” New York Times, October 14,
2020.
38 U.S. Department of Defense, “Statement by Pentagon Press Secretary Peter Cook on U.S. Military Strikes Against
Radar Sites in Yemen,” October. 12, 2016.
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work of the many NGOs providing lifesaving assistance in the country.”39 Aid agencies have
warned that designating the Houthis would deter “commercial shipping, insurance, and trade
companies from working in Yemen for fear of running afoul of U.S. law.”40
Yemen’s Humanitarian Crisis
The United Nations has described Yemen’s humanitarian crisis as the worst in the world, with
close to 80% of Yemen’s population of nearly 30 million needing some form of assistance. As of
mid-November 2020, Yemen’s humanitarian crisis continues to spiral downward due to the
COVID-19 pandemic, depreciation of the Yemeni rial (which has lost over 70% of its value
against the dollar since 2014), and a fuel import shortage caused by Houthi-ROYG disputes at the
contested port of Hudaydah. During the spring and summer, torrential rains caused flood damage
to internal displacement camps. A locust infestation in Yemen and East Africa has caused several
hundred million dollars in crop damages. According to the Famine Early Warning Systems
Network (FewsNet):
Overall, an estimated 17 to 19 million people are expected to be in need of humanitarian
food assistance throughout 2020. Crisis (IPC Phase 3) outcomes are widespread, with
Emergency (IPC Phase 4) outcomes expected in worst-affected governorates. Although not
the most likely scenario, Famine (IPC Phase 5) would be possible if food supply is cut off
for a prolonged period of time.41
International aid agencies continue to seek funds for humanitarian operations, as many programs
are running low on funds. As of mid-November 2020, the United Nations 2020 Response Plan for
Yemen has received $1.5 billion, or about 45 per cent of requirements.42 The top five 2020 donors
to the United Nation’s Yemen response are: (1) the United States, (2) Saudi Arabia, (3) the United
Kingdom, (4) Germany, and (5) the European Union.
In FY2020, the United States provided $630.4 million in total humanitarian assistance. Due to
Houthi obstruction of aid, USAID has continued to withhold $73 million in funding for
humanitarian assistance in Houthi-controlled areas of northern Yemen. Some Members have
written letters to the Administration seeking to restore that funding.43
According to U.N. Under-Secretary-General for Humanitarian Affairs and Emergency Relief
Coordinator, Mark Lowcock, who briefed the Security Council in early November 2020, “In the
north, restrictions have been substantially more severe. There has been important progress on
some of the problems, including assessments and project approvals. And on Sunday, a long-

39 Senator Chris Murphy, Press Statement, “Murphy, Young, Coons Caution Against Designating Houthis in Yemen as
Terrorist Organization,” November 23, 2020.
40 Missy Ryan and John Hudson, “Ahead of Yemen Move, U.N. Highlights Humanitarian Risk, and Officials Prepare
to Suspend Aid,” Washington Post, December 2, 2020.
41 USAID’s Famine Early Warning Systems Network, Food Security Outlook Update, “Conflict and Currency
Shortages Remain of High Concern for Acute Food Insecurity in Yemen,” September 2020.
42 United Nations Security Council, Press Release, SC/14352, “Most Urgent Task in Yemen Is to Prevent Widespread
Famine, Humanitarian Affairs Chief Tells Security Council, as Speakers Push for Nationwide Ceasefire,” November
11, 2020.
43 Representative Ted Deutch, “55 Representatives Urge Pompeo to Restore Humanitarian Assistance to Yemen &
Support Diplomatic Solutions to Conflict,” September 16, 2020 and Senator Ben Cardin, “Cardin, Young Lead Effort
to Continue Humanitarian Lifeline for Yemeni Civilians,” May 12, 2020.
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planned pilot finally began in Sana’a to introduce biometric registration of emergency food aid
recipients.”44
Since 2015, the United States has provided over $3 billion in emergency humanitarian aid for
Yemen (see Table 2 below). Most of these funds are provided through USAID’s Office of Food
for Peace to support the World Food Programme in Yemen.
Table 2. U.S. Humanitarian Response to the Complex Crisis in Yemen:
FY2015-FY2020
(in millions of U.S. dollars)
Account
FY2015
FY2016
FY2017
FY2018
FY2019
FY2020
IDA (USAID/OFDA)
62.030
81.528
229.783
179.065
102.058
116.352
FFP (UDAID/FFP)
71.486
196.988
369.629
368.243
594.548
442.513
MRA (State/PRM)
45.300
48.950
38.125
18.900
49.800
71.580
Total
178.816
327.466
637.537
566.208
746.406
630.445
Source: Yemen, Complex Emergency—USAID Factsheets.
Iranian Support to the Houthis
Iranian knowledge transfer and military aid to the Houthis, in violation of the targeted
international arms embargo (see U.N. Security Council Resolution 2216), has increased the U.N. Security Council Resolution 2216), has increased the
Houthis’ ability to threaten Saudi Arabia and other Gulf nations. According to the United Nations Houthis’ ability to threaten Saudi Arabia and other Gulf nations. According to the United Nations
Panel of Panel of Experts on Yemen, “An increasing body of evidence suggests that individuals or entities in the Islamic Republic of Iran supply significant volumes of weapons and components to the Houthis.”19 In October 2020, Iran appointed Hassan Eyrlo (alt. sp. Irlu) as Ambassador to the so-called “National Salvation Government,” the Houthi-run northern Yemeni authority. The appointment made Iran the first country to diplomatically recognize the Houthis as a legitimate government since they seized control of the capital city of Sana’a in 2014. On December 8, 2020, under the authority of E.O.13224Experts on Yemen, Houthis have received “military support in the form of assault rifles,
rocket-propelled grenade launchers, anti-tank guided missiles and more sophisticated cruise
missile systems. Some of those weapons have technical characteristics similar to arms
manufactured in the Islamic Republic of Iran.”45
The Houthis employ a variety of weapons to project power near and beyond Yemen’s land and
maritime borders, including:
 Short-range Ballistic Missiles - According to various sources, the Houthis have
modified Iranian “Qiam” short-range ‘Scud’ missiles to boost their ranges in
order to threaten Saudi cities, such as the capital Riyadh.46 In May 2018, the U.S.
Department of the Treasury, the U.S. Treasury Department’s Office of Foreign ’s Office of Foreign AssetsAsset Control (OFAC) designated Hassan Eyrlo as a Specially Designated National (SDN) due to his position as an “official in Iran’s Control (OFAC)
designated five Iranian individuals who have “provided ballistic missile-related
technical expertise to Yemen’s Houthis, and who have transferred weapons not
seen in Yemen prior to the current conflict, on behalf of the Islamic Islamic
Revolutionary Guard Corps-Qods Force (IRGC-QF).”47

44 United Nations, Under-Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator, Mark
Lowcock, Briefing to the Security Council on the humanitarian situation in Yemen, November 11, 2020.
45 UN investigators also have uncovered how the Houthis procure foreign components themselves using front
companies. See, Letter dated 27 January 2020 from the Panel of Experts on Yemen addressed to the President of the
Security Council, United Nations Panel of Experts on Yemen, S/2020/70, January 27, 2020.
46 “Letter dated 26 January 2018 from the Panel of Experts on Yemen mandated by Security Council resolution 2342
(2017) addressed to the President of the Security Council,” United Nations Panel of Experts on Yemen, S/2018/68,
January 26, 2018.
47 U.S. Department of the Treasury, Treasury Targets Iranian Individuals Providing Ballistic Missile Support to
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 Long-Range Land Attack Cruise Missiles – On November 22, 2020, the
Houthis claimed to have fired a “Quds-2” cruise missile nearly 400 miles into
Saudi territory, where it struck an oil tank at a Saudi Aramco facility near Jeddah.
The Quds-2 appears to be an upgraded (longer range, more precise) version of an
earlier Houthi cruise missile that United Nations experts believe were sold or
provided to them, possibly by Iran.48 In November 2019, the USS Forrest
Sherman boarded a fishing boat in the Arabian Sea and seized an Iranian
weapons cache bound for Yemen, which included advanced missile components
for land-attack cruise missiles.49
 UAVs – Beginning in 2018, the Houthis began using UAVs to deliver and
detonate explosive payloads against ROYG and Saudi targets. According to
Jane’s Intelligence Weekly, Houthis UAV capabilities gained “increased support
from Iran in terms of the supply of technology and military trainers dispatched to
Yemen.”50 The U.N. Panel of Experts on Yemen reported in January 2019 that the
panel “has traced the supply to the Houthis of unmanned aerial vehicles and a
mixing machine for rocket fuel and found that individuals and entities of Iranian
origin have funded the purchase.”51
 Surface-to-Air-Missiles (SAMs) – In February 2020, the U.S. Navy revealed
that an intercepted Iranian weapons shipment to the Houthis contained a long-
range air-breathing SAM that could loiter in a designated target area.52
 Anti-Ship Missiles, Drone Boats, and Sea Mines – The Houthis have
developed various anti-ship capabilities that can threaten Saudi-led coalition
ships enforcing a maritime blockade against Yemen.53 In February 2020,
CENTCOM discovered that in addition to the previously mentioned weapons
seized by the U.S. Navy, Iran also had shipped Iranian “Noor” anti-ship cruise
missiles (anti-ship missiles based on the Chinese C-802 missile) to the Houthis.
The Houthis also have repeatedly built remote-controlled Unmanned Surface
Vessels (USVs) also known as Waterborne Improvised Explosive Devices
(WBIEDs) using Iranian components.54



Yemen’s Huthis, May 22, 2018.
48 Jon Gambrell, “Yemen Rebels’ Missile Strikes Saudi Oil Facility in Jiddah,” Associated Press, November 24, 2020.
49 U.S. Department of Defense, U.S. Central Command Public Affairs, “U.S. Dhow Interdictions,” February 19, 2020.
50 Ludovico Carlino, “Houthis Selecting more UAVs Over Ballistic Missiles in Arabian Peninsula Attacks, Jane's
Intelligence Weekly, December 6, 2019.
51 Letter dated 25 January 2019 from the Panel of Experts on Yemen addressed to the President of the Security Council,
S/2019/83, United Nations Security Council.
52 John Ismay and Thomas Gibbons-Neff, “New Iranian Missiles Pose Threat to U.S. Aircraft in Yemen, Pentagon
Says,” New York Times, February 19, 2020.
53 The Houthis fired Iran-supplied anti-ship missiles at UAE and U.S. ships in the Red Sea in October 2016, which
prompted U.S. strikes on Houthi-controlled radar installations.
54 “Anatomy of a ‘Drone Boat’,” Conflict Armament Research, December 2017.
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Revolutionary Guard Corps-Qods Force (IRGC-QF) and the Iranian regime’s envoy to the Houthi rebels in Yemen...”20 Eyrlo attended a January 2021 vigil in Sana’a to mark the one-year anniversary of the U.S. killing of former IRGC-QF Commander Qassem Soleimani. Yemen’s Humanitarian Crisis The United Nations has described Yemen’s humanitarian crisis as currently the worst in the world, with close to 80% of Yemen’s population of nearly 30 million needing some form of assistance. In Yemen, myriad factors (e.g., war, loss of health services, funding shortages, currency depreciation) have combined to put the most vulnerable populations at risk. According to various United Nations agencies, acute malnutrition among children under the age of five in Yemen has hit the highest levels ever recorded; nearly 2.3 million children under age 5 in Yemen are at risk of acute malnutrition in 2021.21 Food Insecurity & Humanitarian Access While the international community has not officially declared a famine in Yemen, food insecurity amongst large swaths of the population is increasing (see Figure 5). According to the December 2020 United Nations’ Integrated Food Security Phase Classification (IPC) projections for Yemen, 54% of the population (16.2 million) may experience high levels of acute food insecurity in the first half of 2021. Out of these, U.N. projections indicate an estimated 11 million people will likely be in crisis (IPC Phase 3), 5 million in Emergency (IPC Phase 4), and 47,000 in Catastrophe (IPC Phase 5, famine-like conditions).22 Humanitarian workers have long documented the numerous challenges to working in Yemen, such as lack of access to areas in need of assistance. As Yemen has devolved into various centers of power, aid agencies have had to navigate competing rules and regulations between northern 19 Op.cit.., Panel of Experts on Yemen. 20 U.S. Department of the Treasury, “Treasury Sanctions Iran’s Envoy in Yemen and University Facilitating Recruitment for Qods Force,” Press Release, December 8, 2020. 21 United Nations Office for the Coordination of Humanitarian Affairs, Yemen Situation Report, February 14, 2021. 22 Integrated Food Security Phase Classification (IPC), “Yemen: Acute Food Insecurity Situation October - December 2020 and Projection for January - June 2021.” Congressional Research Service 8 Yemen: Civil War and Regional Intervention and southern Yemen and sometimes within individual governorates. According to one account, “Institutional overlap between rival governments has created numerous logistical issues, such as humanitarian workers needing to obtain duplicate visas and permits from multiple ministries.”23 Figure 5. World Food Programme: Emergency Dashboard Yemen January 2021 Source: World Food Programme, Yemen Emergency Dashboard January 2021, updated February 2021. As the Houthis have become further ensconced in northern Yemen and placed key members in positions of authority, Houthi restrictions on humanitarian aid agencies working in northern Yemen have grown more onerous.24 Control and diversion of aid is one means Houthi forces, Houthi partners, and other parties to the conflict have used to finance their operations.25 23 Jan Egeland, Alex Harper, Emma Beals, and Jomana Qaddour, “Humanitarian Aid and the Biden Administration: Lessons from Yemen and Syria,” Policy Forum Report, The Washington Institute, January 25, 2021. 24 According to senior U.N. officials, Houthi obstructions include: obstacles to beneficiary registration, attempts to divert aid, efforts to control selection of implementing partners, detention and arrest of humanitarian workers, and intimidation and harassment of aid workers at Sana’a airport. See Under-Secretary-General for Humanitarian Affairs and Emergency Relief Coordinator Mark Lowcock, “Briefing to the Security Council on the Humanitarian Situation in Yemen - As Delivered,” New York, NY, September 16, 2019. See also “UN: Houthi Rebels Impeding Aid Flow in Yemen,” Al Jazeera English, February 19, 2020. 25 Sam Kiley, Sarah El Sirgany and Brice Lainé, “CNN exposes systematic abuse of aid in Yemen,” CNN, May 20, 2019. Congressional Research Service 9 Yemen: Civil War and Regional Intervention In 2020, as international frustration over Houthi obstruction of humanitarian assistance mounted, the international community warned that if the Houthis do not abide by the principles of international humanitarian law and allow for unimpeded access for humanitarian assistance, they will risk losing aid. In March 2020, USAID initiated a partial suspension of its funding to support humanitarian operations in northern Yemen. The suspension followed several weeks of warnings from U.S. officials that the Trump Administration was extremely concerned over Houthi obstruction of aid.26 As of March 2021, USAID has continued its partial suspension of $50 million in humanitarian programming in Houthi-controlled areas of Yemen due to continued “Houthi-imposed bureaucratic impediments.” USAID continues to fund more than $13 million in humanitarian NGO activities in northern Yemen for programs that can be conducted without Houthi interference.27 The COVID-19 Pandemic in Yemen The COVID-19 pandemic has added an additional layer of concern for Yemen’s already depleted health system. U.N. statistics from December 2020 indicate a total of 2,103 COVID-19 cases with 611 deaths; most health experts believe that these figures vastly underestimate the extent of COVID-19 in Yemen.28 The United Nations has procured medical equipment, testing kits, and medicine while seeking additional supplies. Aid groups also have increased the capacity of intensive care units (ICUs) in COVID-19 designated hospitals from 38 in May 2020 to 59 as of December 2020.29 The Public Broadcasting Service’s documentary series Frontline has reported on how Houthi authorities in northern Yemen have concealed the impact of COVID-19 in areas under their control. According to one reporter who was permitted to visit northern Yemen in the summer of 2020, Houthi authorities “put out very little public information about the spread of COVID. But they’ve promoted propaganda videos...showing them mobilizing against the virus.”30 The Houthis claim that the Saudi-led coalition’s blockade of Hudaydah and the Sana’a airport have prevented them from procuring the supplies they need to combat the virus. International Pledges for Yemen On March 1, 2021, the United Nations hosted the virtual High Level Pledging Event for the Humanitarian Crisis in Yemen. For 2021, the U.N. is seeking $3.85 billion for operations in Yemen; however, donors pledged $1.7 billion. Secretary Blinken spoke at the event, announcing that the United States would contribute $191 million in additional assistance, bringing total U.S. spending in FY2021 to $350 million. The United States provided $630.4 million in total humanitarian aid for the crisis in Yemen in FY2020, close to the annual average U.S. allocation over the last four fiscal years ($644 million). Secretary Blinken called on other donors, 26 Ambassador Kelly Craft, “Remarks at a U.N. Security Council Briefing on the Situation in Yemen,” U.S. Mission to the United Nations, February 18, 2020. 27 USAID, “Yemen – Complex Emergency, Fact Sheet #1, Fiscal Year (FY) 2021” January 22, 2021. 28 United Nations, COVID-19 Preparedness and Response Monthly Report, December 2020. 29 Op.cit., COVID-19 Preparedness and Response. 30 Public Broadcasting Service, “Yemen’s COVID Cover-Up,” Frontline, February 9, 2021. Congressional Research Service 10 Yemen: Civil War and Regional Intervention “especially those in the region – to step up.”31 Other donations include $430 million from Saudi Arabia, $244 million from Germany, and $230 million from the UAE.32 Conflict Analysis The Biden Administration has made a number of changes in U.S. Yemen policy designed to emphasize its peacemaking role and prioritize efforts to resolve the humanitarian crisis. While the Biden Administration lifted the Trump Administration’s terrorism designations of the Houthis,33 it has targeted additional Houthis leaders using Yemen-specific authorities (E.O. 13611), while also condemning Houthi attacks against civilians and Saudi Arabian territory.34 To date, the Biden Administration has not publicly clarified what it means by its decision to no longer support Saudi-led coalition offensive operations in Yemen, or what its defensive support to Saudi Arabia would entail.35 According to one report, U.S. officials are currently assessing existing and potential sales of U.S. equipment and training to Saudi Arabia in order to determine what U.S. support may be considered defensive.36 Despite these tangible and rhetorical steps, one could argue that developments in the war in northern Yemen may be the most important factor in determining whether outside actors, like the United States, are capable of bringing Yemen’s various internal factions to the negotiating table. A rapid Houthi advance in Marib and/or the seizure its eponymous provincial capital are not a foregone conclusion; for the ROYG government and many northern Yemenis opposed to Houthi rule, it is a last stand. Therefore, fighting has been, and may continue to be, intense, with heavy casualties on both sides. If the Houthis are thwarted, it would signal, at least temporarily, a geographic limit to their rule, and perhaps an incentive for reaching a cease-fire. Such a ceasefire would do little to resolve Houthi control over most of the rest of northern Yemen, including the capital, Sana’a. The extent of Saudi Arabia’s intervention using air power to support ROYG ground forces in Marib may be pivotal, but many questions remain. How Saudi Arabia uses its air power in Marib and elsewhere may greatly depend on understandings between it and the Biden Administration over what constitutes a defensive or offensive air strike. Furthermore, even if Saudi preemptive air strikes against Houthi military targets inside Yemen adhere to understandings between it and the Biden Administration, it remains to be seen how the Biden Administration may react if Saudi air operations kill civilians. U.S. officials have demanded a halt to the Houthi offensive in Marib, 31 U.S. Department of State, Office of the Spokesperson, “Secretary Antony J. Blinken at the 2021 High-Level Pledging Event for the Humanitarian Crisis in Yemen,” Remarks, March 1, 2021. 32 A complete list of donors is available online at www.unocha.org/sites/unocha/files/20210103-YemenHLE2021_AnnouncementsResults.pdf. 33 U.S. Department of State, “Department Press Briefing, February 16, 2021,” Ned Price, Department Spokesperson, February 16, 2021. 34 U.S. Department of State, Office of the Spokesperson, “Houthi Attacks Impacting Civilians,” Press Release, Ned Price, Department Spokesperson, February 7, 2021. 35 In a recent State Department press conference, Spokesperson Ned Price remarked “The broader point is that for any weapons sales or transfers [to Saudi Arabia], there is now a process in place, thanks to President Biden and his efforts to recalibrate this relationship from the start, that will evaluate, on a case-by-case basis, proposed weapons sales and transfers based on two criteria: our interests and our values. And that second point, that latter point, is incredibly important in this case.” See, U.S. Department of State, “Department Press Briefing, March 2, 2021.” 36 Patricia Zengerle and Mike Stone, “Exclusive: Biden Team Considering a Halt to 'offensive' Arms Sales for Saudis,” Reuters, February 26, 2021. Congressional Research Service 11 Yemen: Civil War and Regional Intervention but the Administration has not indicated what specific military, advisory, or assistance steps, if any, it may be willing to take to ensure that outcome. Overall, while many in the international community wish to foster a political solution to the Yemen conflict and thereby alleviate the dire humanitarian conditions, many internal and external parties to the Yemen conflict do not appear presently to have clear political, military, or financial incentives to negotiate. According to the latest U.N. Panel of Experts Report on Yemen, the war in Yemen has witnessed widespread “profiteering and control over economic resources by individuals and entities.”37 For the Houthis, the longer they remain the de-facto authority in northern Yemen, the more their rule becomes an accepted norm, with increased potential that such legitimacy could gain more acceptance internationally. For the STC, the war has provided them with a foreign patron in the UAE and a degree of local autonomy not seen since before the unification of Yemen in 1990. For Iran, its military support to the Houthis has allowed it to again demonstrate how projecting power through proxy warfare is arguably a successful strategy for expanding its regional influence. Finally, while the UAE may have suffered reputational damage due its conduct in the Yemen war, the Emirates have gained influence along several Yemeni coastal port towns and islands, such as Socotra, Mayyun, Belhaf, and Mukalla (see Figure 1). Leaders in Saudi Arabia, who have arguably suffered the most reputational damage over their forces’ conduct in Yemen, may feel motivated to reduce the kingdom’s military footprint in Yemen for a number of reasons including costs, stress on military forces and platforms, and the prospect of improved relations with the United States. However, the Houthis, and more specifically their apparently deepening partnership with Iran, pose a key threat to Saudi security, and military withdrawal seems likely to leave the Houthis’ militia and control over northern Yemen intact. If the Houthis cannot be militarily defeated, then Saudi leaders may weigh whether or not the kingdom should legitimize Houthi rule by lifting its blockade of Yemen and negotiating a cease-fire. Alternatively Saudi Arabia could seek to continue to pressure the Houthis by sponsoring its own Yemeni proxies in the hopes that one day, the balance of power will shift in its favor. Saudi officials also may consider seeking additional U.S. engagement to combat objectionable Iranian intervention in Yemen in connection with broader U.S. efforts to negotiate with Iran over its nuclear program and regional policies. Author Information Jeremy M. Sharp Specialist in Middle Eastern Affairs 37 Op.cit., Panel of Experts. Congressional Research Service 12 Yemen: Civil War and Regional Intervention Disclaimer This document was prepared by the Congressional Research Service (CRS). CRS serves as nonpartisan shared staff to congressional committees and Members of Congress. It operates solely at the behest of and under the direction of Congress. Information in a CRS Report should not be relied upon for purposes other than public understanding of information that has been provided by CRS to Members of Congress in connection with CRS’s institutional role. CRS Reports, as a work of the United States Government, are not subject to copyright protection in the United States. Any CRS Report may be reproduced and distributed in its entirety without permission from CRS. However, as a CRS Report may include copyrighted images or material from a third party, you may need to obtain the permission of the copyright holder if you wish to copy or otherwise use copyrighted material. Congressional Research Service R43960 · VERSION 41 · UPDATED 13Yemen: Civil War and Regional Intervention

Countering Iranian influence in Yemen: Recent U.S. Policy55
U.S. policymakers have pursued several different lines of effort to counter Iranian influence in Yemen, as part of
the Trump Administration’s maximum pressure campaign against Iran. Since the start of the Saudi-led coalition’s
2015 intervention, U.S. naval forces from the Central Command/5th Fleet, in support of international efforts to
enforce a targeted arms embargo, have repeatedly intercepted vessels carrying smuggled Iranian arms destined for
the Houthis off the coast of Yemen.56 In summer 2019, President Trump ordered the deployment of a Patriot air
defense battery to Prince Sultan Air Base in central Saudi Arabia. According to a State Department release at the
time, “We stand firmly with our Saudi partners in defending their borders against these continued threats by the
Houthis, who rely on Iranian-made weapons and technology to carry out such attacks.”57 According to one
report, on the same day the United States kil ed Islamic Revolutionary Guard Corps-Qods Force (IRGC-QF)
Commander Qasem Soleimani in Baghdad, the United States also unsuccessful y targeted IRGC-QF leader Abdul
Reza Shahlai, who was based in Yemen.58 The operation came a few weeks after the U.S. State Department
announced a $15 mil ion reward for information leading to Shahlai’s capture.
U.S. policymakers have repeatedly portrayed Iran as a spoiler in Yemen, bent on sabotaging peace efforts by
supporting Houthi attacks against Saudi Arabia. As with its other proxy groups (e.g., Hezbol ah), Iran uses its
relationship with the Houthis to project power in the region as part of Tehran’s broader national security
strategy. However, as Saudi Arabia has more directly engaged Houthi leadership in peace talks, U.S. officials have
indicated that the Houthis are independent political actors and are not beholden to Iran. According to former U.S.
Special Representative for Iran Brian Hook, “The Houthis’ de-escalation proposal, which the Saudis are responding
to, shows that Iran clearly does not speak for the Houthis, nor has the best interests of the Yemeni people at
heart…. Iran is trying to prolong Yemen’s civil war to project power. Iran should fol ow the calls of its own people
and end its involvement in Yemen.”59 In April 2020, U.S. Secretary of State Michael R. Pompeo spoke with Saudi
Foreign Minister Faisal bin Farhan Al Saud regarding Yemen; both ministers agreed that an “unstable Yemen only
benefits the Iranian regime and that the regime’s destabilizing behavior there must be countered.”60
Saudi-led Coalition Operations in Yemen and Civilian Casualties
From 2015 onward, the number of Members of Congress expressing alarm increased as Saudi and
coalition airstrikes killed and injured Yemeni civilians and damaged civilian infrastructure. The
Royal Saudi Air Force and its coalition partners reportedly use U.S.- and European-origin strike
aircraft and air-to-ground munitions in many of their operations in Yemen. Some reports have
documented the use of U.S.-origin munitions in strikes that have killed and injured civilians.61
Saudi officials have acknowledged shortcomings in their operations, and report that they have
adapted their tactics and operations for the express purpose of reducing civilian harm. They place

55 For more information, see CRS Report R44017, Iran’s Foreign and Defense Policies, by Kenneth Katzman.
56 “Weapons Bound for Yemen Seized on Iran Boat: Coalition,” Reuters, September 30, 2015; “Jason Dunham Seizes
Illicit Arms in Gulf of Aden,” U.S. 5th Fleet Public Affairs, August 30, 2018; and “U.S. Dhow Interdictions,” U.S.
Central Command Public Affairs, February 19, 2020.
57 Department of State, Press Statement: Houthi Attack on Abha Airport in Saudi Arabia, July 2, 2019.
58 Paul Waldman and Greg Sargent, "New Iran Revelations Suggest Trump's Deceptions were Deeper than Thought,"
Washington Post (opinion), January 10, 2020.
59 U.S. State Department, Special Representative for Iran Brian Hook Holds Media Availability, Dec. 5, 2019.
60 U.S. State Department, Secretary Pompeo’s Call with Saudi Foreign Minister Faisal bin Farhan Al Saud, Office of
the Spokesperson, April 1, 2020.
61 For example, see Nima Elbagir, Salma Abdelaziz & Laura Smith-Spark, “Made in America --Shrapnel Found in
Yemen Ties US bombs to String of Civilian Deaths over Course of Bloody Civil War,” CNN, Sept. 18, 2018. Also, see
Situation of Human Rights in Yemen, Including Violations and Abuses since September 2014, Report of the Detailed
Findings of the Group of Eminent International and Regional Experts on Yemen, A/HRC/42/CRP.1, September 3,
2019.
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most of the blame for reported civilian deaths and for difficult humanitarian conditions on the
activities of and threats posed by their adversaries.62
Since the start of the Saudi-led coalition intervention in Yemen in 2015, journalists, human rights
monitors, legal scholars, and some lawmakers have reported that the use of U.S.-supplied military
equipment by Saudi Arabia and the UAE may be in violation of specific provisions in the AECA
and the Foreign Assistance Act (FAA).63 The AECA and FAA prohibit the sale or delivery of
U.S.-origin defense articles if either the President (by determining such and reporting to
Congress) or Congress (by passing a joint resolution) finds that a recipient country has used such
articles “for a purpose not authorized” by Section 4, AECA (22 U.S.C. 2754), Section 502, FAA
(22 U.S.C. 2302), or in substantial violation of other limitations contained in an agreement with
the United States governing the articles' provision (Section 3(c)(1)(B), AECA (22 U.S.C.
2753(c)(1)(B), and Section 505(d), FAA (22 U.S.C. 2314(d)).64 Section 4, AECA, and Section
502, FAA state that defense articles may be sold only for certain purposes, including internal
security, legitimate self-defense, impeding weapons of mass destruction proliferation, and
participation in collective measures requested by the United Nations or comparable organizations.
Legal arguments that violations of U.S. law may have occurred have centered on the idea that
while Saudi Arabia and the internationally-recognized government of Yemen have a right to
collective self-defense,65 the use of force applied in self-defense must be both “necessary” and
“proportionate.”66 In the case of Yemen, some scholars have argued that the indiscriminate
targeting of civilians serves no lawful military purpose and does not deter threats, therefore
failing to meet the legal threshold of necessity and proportionality.67 One reports suggests that
some U.S. State Department officials who have overseen U.S. arms sales have retained their own
legal counsel due to concerns that they would be legally vulnerable for prosecution in foreign
courts that claim universal jurisdiction over war crimes.68

62 See, for example, Remarks of Saudi Minister of State for Foreign Affairs Adel al Jubeir, Council on Foreign
Relations, New York, NY, September 24, 2019.
63 See, for example, Michael Pates and Brittany Benowitz, “An Assessment of the Legality of Arms Sales to the
Kingdom of Saudi Arabia in the Context of the Conflict in Yemen,” American Bar Association, May 19, 2017.
64 See CRS In Focus IF11533, Modifying or Ending Sales of U.S.-Origin Defense Articles, by Paul K. Kerr and Liana
W. Rosen.
65 In 2015, President Hadi requested international assistance from the Gulf Cooperation Council (GCC) to defend his
government against attacks by the Houthis. See, President Hadi correspondence with GCC governments printed in U.N.
Document S/2015/217, “Identical letters dated 26 March 2015 from the Permanent Representative of Qatar to the
United Nations addressed to the Secretary-General and the President of Security Council,” March 27, 2015.
66 Oona A. Hathaway, Aaron Haviland, Srinath Reddy Kethireddy, and Alyssa T. Yamamoto, “Yemen: Is the U.S.
Breaking the Law?” Harvard National Security Journal / Vol. 10, 2019.
67 op.cit., American Bar Association.
68 Michael LaForgia and Edward Wong, “War Crime Risk Grows for U.S. Over Saudi Strikes in Yemen,” New York
Times, September 14, 2020.
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Congress has taken several steps in recent
Figure 3. Yemen: Reported Air Strikes and
years to exercise additional oversight of
Related Civilian Fatalities, 2015- March 2020
the Saudi military’s use of U.S.-origin
Armed Conflict Location and Event Data Project
air-to-ground munitions and other
weapons in Yemen and to reject proposed
sales of additional U.S. munitions and
other arms to the Saudi military.69
President Trump has vetoed joint
resolutions of disapproval, allowing arms
sales to continue.
In testimony before Congress, State
Department and Defense Department
officials have acknowledged the
occurrence of civilian casualties in Saudi
and coalition airstrikes, while reiterating
that the United States has provided the
Saudi-led coalition with training on
targeting, and has provided mentoring
and advising on best practices to reduce
civilian casualties.70 The Trump
Administration has argued that the supply
to Saudi Arabia of more precise air to
ground munitions contributes to fewer
civilian casualties than otherwise might
occur. Prior to ending U.S. refueling for
Saudi and coalition aircraft operating
over Yemen in November 2018,
Administration officials argued that such

support improved the ability of partner
Source: Armed Conflict Location and Event Data Project
(ACLED) and Yemen Data Project, March 2020.
forces to conduct reconnaissance and
avoid errant strikes.71
Notes: Reformatted by CRS.

U.S. Counterterrorism Operations in Yemen
According to President Trump’s June 2020 report to Congress on the deployment of U.S. Armed
Forces abroad, “A small number of United States military personnel are deployed to Yemen to
conduct operations against al-Qa’ida in the Arabian Peninsula (AQAP) and ISIS. The United
States military continues to work closely with the Republic of Yemen Government (ROYG) and
regional partner forces to degrade the terrorist threat posed by those groups.”72

69 CRS Report R45046, Congress and the War in Yemen: Oversight and Legislation 2015-2020, reviews these steps in
detail.
70 See, for example, Testimony of R. Clarke Cooper, Assistant Secretary Of State, Political-Military Affairs, House
Foreign Affairs Committee, June 12, 2019.
71 Ibid.
72 White House, Text of a Letter from the President to the Speaker of the House of Representatives and the President
pro tempore of the Senate, June 9, 2020.
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Throughout the Yemen crisis the United States has sustained counterterrorism operations against
various U.S.-designated Foreign Terrorist Organizations. U.S. forces, at times working with Saudi
Arabia and the ROYG, have killed or captured the leaders of both AQAP and the Yemeni branch
of the Islamic State. On February 6, 2020, the White House issued a statement that U.S. forces
had killed then-current leader and one of the founders of AQAP, 41-year-old Qasim al Rimi (also
spelled Raimi or Raymi).73 Rimi’s successor is 41-year-old Khalid Batarfi who, according to one
expert, “trained and fought in Afghanistan prior to September 2001, assisted fighters traveling to
Iraq following the U.S. invasion in 2003, and helped lead AQAP’s push to seize territory in
southern Yemen in 2010 and 2011.”74
The announcement of Rimi’s death came several days after Rimi released an audiovisual message
claiming that AQAP was responsible for the December 2019 attack at the Naval Air Station
Pensacola in Pensacola, Florida that killed three U.S. soldiers and wounded eight others. That
attack was carried out by a Saudi soldier, Second Lt. Mohammed Alshamrani, who had been
enrolled in a training program developed to teach Saudi pilots how to reduce civilian casualties in
Yemen. Subsequent investigations of the terrorist attack in Pensacola have revealed that the
radicalization of the Saudi soldier and AQAP’s role in it was complicated. According to one
account:
One reason Lieutenant Alshamrani proved so difficult to detect...was that he represented a new
kind of terrorist. He was not directed start to finish by Al Qaeda, nor was he simply inspired by
online jihadist ideology. Instead he more closely resembled a self-directed contractor who was
strongly enabled by Al Qaeda’s Yemeni branch.75
U.S. counterterrorism operations combined with ongoing civil strife in Yemen have forced AQAP
underground. According to one assessment, “The group’s quasi-hibernation could be extended or
brief, depending on the uncertainty of the conflict in Yemen as well as the timing of its
development of new operatives, which take time to recruit and train.” 76 Overall, AQAP’s ability
to directly carry out attacks abroad has diminished due to U.S. counterterrorism efforts; therefore
the group has shifted focus onto “inspiring rather than directing attacks.”77
ISIS announced the formation of its Yemeni affiliate, composed mostly of disaffected AQAP
fighters, in 2014, and has launched attacks against both Houthi targets as well as the Saudi-
backed ROYG. In June 2019, Saudi Arabia and ROYG troops captured the leader of the Yemeni
branch of the Islamic State in the far eastern governorate of Al Mahra. Reportedly, the United
States played an “advise and assist” role during the operation.78
To date, two U.S. soldiers have died in the ongoing counterterrorism campaign against AQAP and
other terrorists inside Yemen. In January 2017, Ryan Owens, a Navy SEAL, died during a
counterterrorism raid in which between 4 and 12 Yemeni civilians also were killed, including
several children, one of whom was a U.S. citizen. The raid was the Trump Administration’s first
acknowledged counterterror operation. In August 2017, Emil Rivera-Lopez, a member of the elite

73 White House, Statement from the President, February 6, 2020.
74 Gregory D. Johnsen, “Khalid Batarfi and the Future of AQAP,” Lawfare, March 22, 2020.
75 Michael LaForgia and Eric Schmitt, “The Lapses That Let a Saudi Extremist Shoot Up a U.S. Navy Base,” New York
Times, June 21, 2020.
76 Mitch Prothero, “AQAP Dispersion amid Broader Yemeni Conflict Underlines Strategic Depth and Organisational
Resilience,” Jane's Terrorism & Insurgency Monitor, November 6, 2020.
77 “After US Killing of Chief, What's Next for AQAP?” Agence France Presse, August 2, 2020.
78 “Saudi Arabia announces Capture of an ISIS leader in Yemen in U.S.-backed Raid,” Washington Post, June 25,
2019.
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160th Special Operations Aviation Regiment, died when his Black Hawk helicopter crashed off
the coast of Yemen during a training exercise.
According to one study, since 2002, the United States has conducted 374 air, drone, or ground
operation strikes against terrorist targets in Yemen, killing an estimated 1,376– 1,773 militants
and 115– 149 civilians.79 Among those militants killed were high-value targets such as AQAP
leader Qasim al Rimi (2020); AQAP bomb maker Ibrahim al Asiri, (2018); AQAP leader Nasser
al Wuhayshi (2015); USS Cole bomber Fahd al Quso (2012); and AQAP cleric/U.S.-citizen
Anwar al Awlaki (2011).
Possible Illegal Transfer of U.S. Weaponry in Yemen
Congress has long taken an interest in ensuring that arms sold to foreign countries are used
responsibly and for the purposes agreed on as part of their sale.80 In February 2019, CNN reported
that Saudi Arabia and the UAE had provided U.S. armored vehicles to local Yemeni units fighting
the Houthis in possible violation of end-user provisions in foreign military sale or direct
commercial sale agreements.81 The coalition denied that the items had left their control, citing
command arrangements (see below), while the State Department said that it was “seeking
additional information” on the issue. In Senate and House hearings in early February 2019, some
Members expressed concern about end-use monitoring of equipment provided to the coalition.82
In October 2019, CNN published another article alleging that the UAE had illegally transferred
U.S.-made Mine-Resistant Ambush Protected (MRAP) vehicles to the Southern Transitional
Council (STC).83 A third piece, published a month later by CNN, which depicted video footage of
MRAPs being offloaded in Aden, elicited a response from an unnamed State Department official
who remarked that “there is currently no U.S. prohibition on the use of U.S.-origin MRAPs by
Gulf coalition forces in Yemen.”84
Per Section §3(a) of the Arms Export Control Act (AECA - 22 U.S. Code §2753) and Section
505(e) of the Foreign Assistance Act (22 U.S. Code §2314), the U.S. government must review
and approve any transfer of U.S.-origin equipment from a recipient to a third party that was not
previously authorized in the original acquisition.85 Third Party Transfer (or TPT) is the retransfer
of title, physical possession, or control of defense articles from the authorized recipient to any
person or organization that is not an employee, officer or agent of that recipient country.86 U.S.

79 New America, America’s Counterterrorism Wars, The War in Yemen, accessed in April 2020, available online at:
[https://www.newamerica.org/international-security/reports/americas-counterterrorism-wars/the-war-in-yemen/
80 See CRS Report R44984, Arms Sales in the Middle East: Trends and Analytical Perspectives for U.S. Policy, by
Clayton Thomas.
81 Nima Elbagir, Salma Abdelaziz, Mohamed Abo El Gheit and Laura Smith-Spark, "Sold to an Ally, Lost to an
Enemy," CNN.com, February 2019. Available at: https://www.cnn.com/interactive/2019/02/middleeast/yemen-lost-us-
arms/.
82 “Hearing to Receive Testimony on the United States Central Command in Review of the Defense Authorization
Request for Fiscal Year 2020 and the Future Years Defense Program,” Senate Armed Services Committee, February 5,
2019; “Hearing on U.S. Policy in the Arabian Peninsula,” House Foreign Affairs Committee, February 6, 2019.
83 Nima Elbagir, Mohamed Abo El Gheit, Florence Davey-Attlee, and Salma Abdelaziz, “American Weapons Ended
up in the Wrong Hands in Yemen. Now they're Being Turned on the US-Backed Government,” CNN.com, October 20,
2019.
84 Nima Elbagir, Salma Abdelaziz, Mohamed Abo El Gheit, Florence Davey-Attlee and Ed Upright, “Under Shroud of
Secrecy US Weapons Arrive in Yemen Despite Congressional Outrage,” CNN.com, November 7, 2019.
85 See, U.S. State Department, Third Party Transfer Process and Documentation, Bureau of Political-Military Affairs,
December 17, 2018.
86 See, Defense Institute of Security Cooperation Studies, "The Management of Security Cooperation (Green Book),"
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origin defense articles sold via Foreign Military Sales (FMS) and Direct Commercial Sales (DCS)
are subject to end-use monitoring (EUM) to ensure that recipients use such items solely for their
intended purposes.87 DOD’s Defense Security Cooperation Agency manages the department’s
Golden Sentry EUM program for defense articles sold via FMS. The State Department's
Directorate of Defense Trade Controls coordinates the Blue Lantern program, which performs an
analogous function for items sold via DCS.
For lawmakers, the definition of the “end-user” is at issue in Yemen. Saudi Arabia and the UAE
claim that U.S.-purchased weapons used in Yemen have remained in their control in accordance
with U.S. law and relevant bilateral agreements. According to Saudi-led coalition spokesperson
Col. Turki Al Maliki, “the information that the military equipment will be delivered to a third
party is unfounded…. all military equipment is used by Saudi forces in accordance with term and
conditions of Foreign Military Sales (FMS) adopted by the US government and in pursuance of
the Arms Export Control Act.”88
Several Members of Congress have followed up on CNN’s investigations with legislative
inquiries. Senator Elizabeth Warren has sent several letters to the Secretary of Defense and
Secretary of State requesting information regarding the reported transfer of American weapons
from the Saudi-led coalition to armed Yemeni militias, such as the STC.89 In September 2019, the
Senate Appropriations Committee adopted an amendment by voice vote and incorporated it into
Section 9018 of S. 2474, the Department of Defense Appropriations Act, 2020, which would have
prohibited defense funds from being used to support the Saudi-led coalition air campaign in
Yemen until the Secretary of Defense certifies that the Saudi-led coalition is in “compliance with
end-use agreements related to sales of United States weapons and defense articles;” and submits
to Congress any written findings of “any internal Department of Defense investigation into
unauthorized third-party transfers of United States weapons and defense articles in Yemen and
has taken corrective action as a result of any such investigation.” P.L. 116-93, the Consolidated
Appropriations Act, 2020, which incorporated S. 2474, did not include Section 9018.
In May 2020, CNN reported that the State and Defense departments concluded their investigation
into the possible illegal transfer of U.S. equipment and determined that the UAE had been
cleared, adding that the “State Department has told some leaders in Congress that it is ‘satisfied
no actual transfers were made.’”90 On May 7, 2020, the Defense Security Cooperation Agency
(DSCA) notified Congress of a possible Foreign Military Sale to the UAE of Excess Defense
Articles (EDA) of up to 4,569 MRAP vehicles for an estimated cost of $556 million.
U.S. Bilateral Aid to Yemen
Since the current conflict began in March 2015, the United States has increased its humanitarian
assistance to Yemen while limiting nearly all other bilateral programming. On February 11, 2015,
due to the deteriorating security situation in Sana’a, the State Department suspended embassy
operations and U.S. Embassy staff was relocated to Saudi Arabia.

Edition 39, January 2019.
87 Pursuant to Sections 38(g)(7) and 40A(a) of the AECA (22 U.S.C. 2778(g)(7) and 2785(a)), and Section 505(a)(3) of
the FAA (22 U.S.C. 2314(a)(3)).
88 op.cit., CNN, November 7, 2019.
89 Warren Calls on DoD and State to Respond to Reports that American Military Weapons Have Been Transferred to
Suspected Terrorists and Separatist Militias in Yemen, October 23, 2019.
90 Nima Elbagir, Alison Main, Salma Abdelaziz, Laura Smith-Spark and Jennifer Hansler, “The US Cleared the Way
for a New Arms Sale to the UAE, Despite Evidence it Violated the Last One,” CNN, May 22, 2020.
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Over the past few years, USAID has managed an economic assistance portfolio of $25-$30
million. It has focused its programming on the health, education, and financial sectors. In the
health sector, USAID has supported programs for providing polio surveillance, reducing child
mortality, and providing basic access to health care. In the education sector, USAID funds
programs to expand access to education to meet the needs of crisis-affected children. In the
financial sector, USAID has worked with The Central Bank of Yemen (CBY) to ensure that the
CBY can continue paying public sector salaries and managing the treasury.
The Joint Explanatory Statement accompanying the FY2020 Foreign Operations Appropriations
Act (Division G of P.L. 116-94) directs that $40 million in funding made available by the act and
prior acts be used “for stabilization assistance for Yemen, including for a contribution for United
Nations stabilization and governance facilities, and to meet the needs of vulnerable populations,
including women and girls.”
Table 3. U.S. Bilateral Aid to Yemen: FY2016-FY2021 Request
(in millions of U.S. dollars)
FY2016
FY2017
FY2018
FY2019 FY2020 est.
FY2021
Account
Request
ESF
70.0
40.0
25.0
32.0
29.6
26.350
FMF
25.0
–
–
–
–
–
GHP-USAID
9.5
9.0
3.5
5.5
5.5
5.5
IMET
1.4
–
–
–
–
–
INCLE
2.0
1.0
–
.300
.300
–
NADR
6.5
5.884
6.5
5.6
5.6
4.6
Total
114.400
55.884
35.000
43.400
41.400
36.450
Source: Congressional Budget Justifications, USAID notifications, and CRS calculations.
Note: In FY2019, Yemen received $21.5 mil ion in ESF-OCO from the Relief and Recovery Fund.
Recent Legislation
In Congress, several national security-related bills contain provisions on Yemen. H.R. 7608, the
State, Foreign Operations, Agriculture, Rural Development, Interior, Environment, Military
Construction, and Veterans Affairs Appropriations Act, 2021 would prohibit State Department
funds from being used to facilitate the transfer or sale of air-to-ground munitions to Saudi Arabia
and the UAE “in recognition of the continuing devastation to civilians caused by US-provided
weapons in the Yemen conflict.” The bill also contains a reporting requirement that addresses the
delivery of humanitarian assistance. Also in the House, H.R. 6395, the National Defense
Authorization Act for Fiscal Year 2021, would: (1) prohibit U.S. military participation against the
Houthis; (2) require a report on U.S. military support for the Saudi-led coalition; and (3) require a
report on U.S. policy in Yemen. The Conference Report did not include the prohibition on U.S.
military participation, but did include two modified reporting requirements (Sections 1295 and
1296) requesting a detailed description of U.S. diplomatic actions to ease human suffering in
Yemen and a Comptroller General report of “all military support, training, and defense articles
and services provided by the Department of Defense to Saudi Arabia, the Government of the
United Arab Emirates, and other countries participating in the Saudi-led coalition since March
2015.”
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H.R. 7856, the Intelligence Authorization Act for Fiscal Year 2021, would prohibit funds for the
U.S. intelligence community from being expended on intelligence sharing “for the purpose of
enabling or assisting air strikes in Yemen by the Saudi Arabia-led coalition” with the exception of
countering terrorist groups, like Al Qaeda in the Arabian Peninsula. The bill also would require
the Director of National Intelligence to report, among other things, “any incident that has
occurred since 2015 in which Saudi Arabia or one of its coalition partners has been determined to
have used United States weapons against civilians or civilian objects in Yemen.”
Finally, H.Con.Res. 123, would, pursuant to section 5(c) of the War Powers Resolution (50
U.S.C. 1544(c)), direct the President to remove United States Armed Forces from hostilities
against the Houthis in the Republic of Yemen, except United States Armed Forces engaged in
operations directed at Al Qaeda in the Arabian Peninsula or associated forces.
Trump Administration Policy and Outlook for the
Incoming Administration
During the Trump Administration, stated U.S. policy toward Yemen has been generally consistent
with previous administrations. That is, from 2017 to 2020, the United States aimed to counter
terrorism in Yemen, support United Nations efforts to foster political solutions to Yemen’s
conflicts, and provide aid to alleviate the world’s worst humanitarian crisis.91 During the Trump
Administration, there have been few high level diplomatic attempts to directly mediate Yemen’s
numerous internal conflicts. Instead, policymakers have deferred direct peacemaking to U.N.
negotiators and subsumed Yemen into a broader regional policy aimed at improving U.S. ties to
Gulf Arab partners and applying maximum pressure on Iran.
To that end, the Administration has largely been supportive of the Saudi-led coalition’s campaign
in Yemen, with the exception of instances in which Congressional pressure92 altered the
Administration’s approach, or Yemen’s deteriorating humanitarian situation necessitated a change
in U.S. policy. For example, in 2017, as aid delivery to northern Yemen stalled over a Saudi-led
coalition blockade, President Trump pressured the coalition to permit aid shipments.93 In 2018, as
Houthi and Saudi-led coalition forces were battling in streets of Hudaydah and Members of
Congress were expressing outrage at Saudi Arabia over the murder in Turkey of journalist Jamal
Khashoggi, the Administration applied pressure to the coalition to reach a cease-fire in Hudaydah
and unilaterally announced that it would cease in-flight refueling of coalition aircraft.94
Since 2019, as the Houthis have become more aggressive in attacking Saudi territory and
besieging the last ROYG stronghold in northern Yemen, the Trump Administration has refocused

91 U.S. State Department, United States Announces Additional Humanitarian Assistance to the People of Yemen,
February 26, 2019.
92 See CRS Report R45046, Congress and the War in Yemen: Oversight and Legislation 2015-2020, by Jeremy M.
Sharp, Christopher M. Blanchard, and Sarah R. Collins.
93 See, The White House, Office of the Press Secretary, Statement by President Donald J. Trump on Yemen, December
06, 2017. Other statements include: The White House, Office of the Press Secretary, White House Statement on
Iranian-Supported Missile Attacks Against Saudi Arabia, November 8, 2017; The White House, Office of the Press
Secretary, Statement from the Press Secretary on the Humanitarian Crisis in Yemen, November 24, 2017; The White
House, Office of the Press Secretary, Statement by the Press Secretary Regarding the Violence and Humanitarian
Conditions in Yemen, December 08, 2017.
94 On November 9, 2018, then Secretary of Defense James Mattis announced that the coalition would use its own
military capabilities—rather than U.S. capabilities—to conduct in-flight refueling in support of its operations in
Yemen. See White House, Statement of Administration Policy on S.J.Res. 54, November 28, 2018.
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its Yemen policy to emphasize even more how Iran’s support for the Houthis is exacerbating
conflict.95 As previously mentioned, the U.S. Defense Department has displayed caches of seized
advanced weapons of possible Iranian origin destined for the Houthis. In addition, the United
States also may have unsuccessfully targeted a high-level Islamic Revolutionary Guard Corps
(IRGC) operative based in Yemen. Nevertheless, at times, U.S. officials have recognized that
there is some divergence between Houthi and Iranian interests. According to one senior U.S. State
Department official, “I think there are elements within the Houthi movement who recognize that
their link to Iran isn’t in their interest.”96
As 2021 approaches and Yemen continues to be the world’s worst humanitarian crisis, made
worse by the COVID-19 pandemic, some Members of Congress have urged U.S. officials to
become more directly involved in resolving the conflict.97 During the 2020 presidential campaign,
then-candidate Joseph Biden promised to “end our support for the Saudi-led war in Yemen.”98
How the presumed incoming Administration will handle issues pertaining to Yemen remains to be
seen, and it is unclear whether Biden would limit all U.S. support for the coalition, become more
directly involved in conflict mediation, or some combination thereof. Possible policy options
under consideration may include limiting U.S. intelligence sharing and security cooperation with
the Saudi-led coalition, or prohibiting sales of U.S. weapons to Gulf Arab partners which could be
used to harm civilians in regional conflict zones such as Libya, Syria, and Yemen. The next
administration’s handling of a recent Congressional notification of a possible Foreign Military
Sale to the UAE of MQ-9B Remotely Piloted Aircraft for an estimated cost of $2.97 billion may
be instructive.99

Author Information

Jeremy M. Sharp

Specialist in Middle Eastern Affairs


95 See U.S. State Department Press Statements on Yemen, available online here: [https://www.state.gov/countries-
areas-archive/yemen/]
96 U.S. State Department, “Senior State Department Official on Developments in Yemen,” Special Briefing, February
25, 2020.
97 Senator Chris Murphy, Murphy, Young Lead Bipartisan Call for Pompeo to Facilitate Diplomatic Solution to End
Yemen War, June 16, 2020.
98 Joseph R. Biden Jr., “Why America Must Lead Again, Rescuing U.S. Foreign Policy After Trump,” Foreign Affairs,
March/April 2020.
99 Defense Security Cooperation Agency, United Arab Emirates – Mq-9b Remotely Piloted Aircraft, Transmittal No
21-05, November 10, 2020.
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Congressional Research Service
R43960 · VERSION 39 · UPDATED
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