May 16, 2019
U.S.-Iran Tensions Escalate
Overview
determined by the Administration to have conducted
U.S.-Iran tensions have escalated in recent weeks as the
significant transactions with Iran’s iron, steel,
Trump Administration has taken several significant steps in
aluminum, or copper sectors. These commodities
its campaign of applying “maximum pressure” on Iran, and
account for about 10% of Iran’s exports, but the exports
Iranian leaders have announced responses. U.S. steps have
primarily go to regional companies that might not be
included designating Iran’s Islamic Revolutionary Guard
easily penalized by U.S. sanctions.
Corps (IRGC) as a Foreign Terrorist Organization (FTO),
reimposing sanctions on any country that buys Iranian oil,
ending sanctions waivers for some assistance to the
[The U.S. military deployments] send a clear
permitted aspects of Iran’s nuclear program, and imposing
and unmistakable message to the Iranian
new sanctions on transactions in some Iranian commodities.
regime that any attack on United States
U.S. officials state that reports about potential Iran-linked
interests or on those of our allies will be met
threats to U.S. forces and interests prompted the
with unrelenting force.
Administration to send additional military assets to the
Statement by National Security Adviser John Bolton,
region. Yet, press reports on May 16 indicate that President
May 5.
Donald Trump prefers a diplomatic solution to continued

escalation that could lead to conflict.
What they [Iranian leaders] should be doing is
calling me up, sitting down; we can make a
Members of Congress have been requesting additional
deal, a fair deal. ... We're not looking to hurt
information from the Administration about the uptick in
Iran…But they should call, and if they do, we're
U.S.-Iran tensions. Congress might consider the broader
open to talk to them.
Administration’s Iran policy or the potential for use of force
President Donald Trump, May 9.
against Iran.

We don’t seek a war, and they don’t either.
Recent Administration Steps to Pressure Iran
They know it’s not in their interests.
Recent Administration efforts to increase pressure on Iran’s
Iran’s Supreme Leader Grand Ayatollah Ali Khamene’i,
economy and government include:
May 14.
 On April 8, 2019, the Administration designated the

IRGC as a Foreign Terrorist Organization (FTO). Iran’s
parliament responded by enacting legislation declaring
Iranian Reaction
U.S. Central Command (CENTCOM) and related forces
Iran’s reaction to the U.S. steps appears to reflect an
in the Middle East to be terrorists.
attempt to avoid outright conflict with the United States

while indicating that Iran will not bow to U.S. pressure.
As of May 2, 2019, the Administration ended a U.S.
Some Iranian statements have appeared provocative,
sanctions exception for the purchase of Iranian oil to try
including threats by the IRGC Navy Commander to close
to drive Iran’s oil exports to “zero.”
the Strait of Hormuz if Iran could not export any oil, but

Iran historically has issued similar threats that are not
On May 3, 2019, the Administration ended waivers
followed by concrete actions. On the other hand, in May
under the Iran Freedom and Counter-Proliferation Act
2019, Iranian Foreign Minister Mohammad Javad Zarif’s
(IFCA, P.L. 112-239) that allow countries to help
offered to negotiate a swap of detainees held by both sides.
remove Iranian heavy water and low-enriched uranium
that exceed JCPOA stockpile limits.
On May 8, President Hassan Rouhani announced that Iran

would no longer abide by restrictions of the 2015
On May 5, 2019, citing reports that Iran might be
multilateral nuclear agreement (Joint Comprehensive Plan
preparing its allies to attack U.S. personnel or
of Action, JCPOA) on stockpiles of low-enriched uranium
installations, National Security Adviser John Bolton
and heavy water. He also announced that unless the
announced that the United States was accelerating the
European Union (EU) countries that have sought to
previously planned deployment of the U.S.S. Abraham
preserve the JCPOA “fulfill their commitments” to provide
Lincoln Carrier Strike Group to the region and sending a
economic benefits of the JCPOA within 60 days, Iran
bomber task force to the Persian Gulf region.
would resume additional aspects of uranium enrichment,

including possibly enriching to a higher level of purity.
On May 8, the President issued Executive Order 13871,
blocking the U.S.-based property of persons and entities
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U.S.-Iran Tensions Escalate
European Responses
the region, particularly in the Arab states of the Gulf
The EU has sought to de-escalate tensions and urged Iran
Cooperation Council (GCC: Saudi Arabia, Kuwait, UAE,
not to leave the accord entirely. A May 9 joint statement by
Qatar, Oman, and Bahrain). Press reports indicated that the
the EU and the foreign ministers of France, the United
number of forces might expand to up to 120,000 if the
Kingdom, and Germany stated that “We reject any
reported option is exercised. On May 14, President Trump
ultimatums” by Iran but, “At the same time we recall our
dismissed the report, saying “We have not planned for
own firm commitments under the agreement including as
that.” But he added that “If we did that, we’d send a hell of
regards sanctions lifting…” Secretary of State Pompeo
a lot more troops than that.” Whether the Administration
attended meetings with EU officials on May 13, reportedly
adds forces to the region, the United States has the
to brief the EU on U.S. information about alleged Iranian
capability to implement a range of options such as air
planning for attacks on U.S. interests in the region, but
strikes on Iranian targets.
press reports indicate that EU officials are skeptical that
actions by Iran represent a materially new threat. UK
Status Quo. The tensions could remain, but neither escalate
Foreign Secretary Jeremy Hunt stated, “We [EU] are very
nor de-escalate, particularly if the U.S.-Iran discourse
worried about the risk of a conflict happening by accident,
remains mostly bellicose but without any significant violent
with an escalation unintended really on either side.”
incidents that are attributed to either the United States or
Iran.
Scenarios and Possible Outcomes
There are several directions the escalating tensions might
De-Escalation. Iran could potentially try to de-escalate,
take, any of which might involve congressional oversight,
perhaps by taking up U.S. offers to negotiate a broader,
potential considerations of new sanctions, authorization or
revised JCPOA, though U.S. demands for a new JCPOA are
limitations on the use of military force, or congressional
extensive and many see that as unlikely. De-escalation
steps to support regional partners that could be affected by
could also involve mediation by regional states such as
possible conflict. Iran’s Islamic Revolutionary Guard Corps
Oman or Qatar, which have ties to both Iran and the United
–Qods Force (IRGC-QF) arms, trains, and advises allies
States. Qatar’s Foreign Minister visited Iran on May 15
and proxies throughout the Middle East region, including in
reportedly to discuss de-escalation of the U.S.-Iran tensions.
Syria, Lebanon, Iraq, Yemen, and Bahrain. Accordingly,
A May 16 Washington Post report indicated that President
Iran and/or its allies have numerous ways to take aggressive
Trump wants to de-escalate tensions, avoid conflict with
action or counter U.S. actions. The published State
Iran, and negotiate a revised JCPOA.
Department report on international terrorism has
consistently asserted that Iran and its key ally, Lebanese
Potential Implications for Congress of Escalation
Hezbollah, have a vast network of agents in Europe, Latin
The reports of Administration plans for possible military
America, and elsewhere that could act against U.S.
action against Iran reportedly prompted some in Congress
personnel and interests far outside the Middle East.
to request that the Administration brief Congress on its Iran
plans and policies, and Members might explore a number of
On May 15, the State Department ordered “nonemergency
questions in engaging executive branch officials.
U.S. government employees” to leave U.S. diplomatic
facilities in Iraq. This led to speculation that the
One question is that of authorization for the use of military
Administration sees a heightened threat of Iranian allies
force against Iran. No legislation has been enacted
acting against the United States there. In addition, U.S.
authorizing the use of force against Iran, although
Central Command issued a statement that recent comments
successive Presidents have asserted legal and constitutional
of the Baghdad-based British deputy commander of
authority to initiate any military operation. At a Senate
Operation Inherent Resolve (OIR) “run counter to the
Foreign Relations Committee hearing on April 10, 2019,
identified credible threats” from Iran or allied militias in
Secretary of State Pompeo, when asked if the
Iraq or Syria.
Administration considers the use of force against Iran as
authorized, answered that he would defer to Administration
Escalation. U.S. and Iranian officials have said they do not
legal experts on that question. However, he suggested that
want armed conflict. However, the tensions have the
the 2001 authorization for force against those responsible
potential to evolve to that point, perhaps by miscalculation.
for the September 11 terrorist attacks could potentially
Assertions on May 12-13 by the United Arab Emirates and
apply to Iran, asserting that “[Iran has] hosted Al Qaida.
Saudi Arabia that several of their oil tankers had been
They have permitted Al Qaida to transit their country.
“sabotaged” or “vandalized” and reports of attacks on Saudi
There-there’s no doubt there is a connection between the
oil pipeline infrastructure signal the potential for any
Islamic Republic of Iran and Al Qaida. Period. Full stop.”
incident to raise the risk of a clash that may or may not
A relevant, pending item of legislation in the 116th
escalate into wider conflict. Iran denied involvement in the
Congress, the Prevention of Unconstitutional War with Iran
incidents, but findings of responsibility for the tanker
Act of 2019 (H.R. 2354/S. 1039) would prevent the use of
incidents have not been publicized.
funds for “kinetic military operations in or against Iran”
except to repel or prevent an imminent threat to the United
A New York Times report on May 14 indicated that the
States.
Administration might significantly increase the U.S. force
posture in the region if Iran attacks U.S. interests or takes
Kenneth Katzman, Specialist in Middle Eastern Affairs
steps toward developing a nuclear weapon. There are over
60,000 U.S. forces stationed in various military facilities in
IF11212
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U.S.-Iran Tensions Escalate


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https://crsreports.congress.gov | IF11212 · VERSION 1 · NEW

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