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Updated January 10, 2025
Turkey (Türkiye), the PKK, and U.S. Involvement: Chronology
Turkey’s (alt. Türkiye) decades-long struggle with the Kurdistan Workers’ Party (Kurdish acronym PKK) has fostered both cooperation and contention between the United States and Turkey. The PKK, a U.S.-designated foreign terrorist organization (or FTO), represents one among many strands of organized political and military activity in the name of Kurdish nationalism. Since 2015, the United States has partnered with militias that include the PKK-linked Syrian Kurdish People’s Protection Units (Kurdish acronym YPG) against the Islamic State. Turkish military operations in northern Syria to counter the YPG’s militias and reduce its territorial control have been a factor in complicating U.S. policy and U.S.-Turkey relations. During a 2019 Turkish-led incursion into Syria against the YPG, Congress debated sanctions on Turkey, and the Trump Administration briefly imposed some (via Executive Order 13894, which remains in effect). Since the December 2024 ouster of Bashar al Asad in Syria, renewed fighting between Turkey-backed and YPG-led forces has prompted renewed congressional attention.
PKK Origins (1978-1983)
The early Turkish Republic (founded in 1923) saw several Kurdish-led rebellions and uprisings, leading the Turkish state to generally repress Kurdish ethnic identity and political aspirations. In this context, Abdullah Ocalan (born about 1947 in southeastern Turkey’s Sanliurfa Province) and other Kurdish activists founded the PKK in Turkey in the late 1970s as a Marxist-Leninist organization dedicated to an independent Kurdistan. Ocalan built networks that allowed PKK militants to train with Palestinian groups in Syria and Lebanon and base operations from camps in semi-autonomous Kurdish areas of northern Iraq.
1978 Abdullah Ocalan and others establish the PKK.
1979 Ocalan arrives in Syria to lead the PKK from exile.
1980 Military coup in Turkey; general post-coup crackdown on political opposition, including Kurds.
1982 During the Iran-Iraq war, Iran persuades Iraqi Kurdistan Democratic Party (KDP) leader Masoud Barzani to allow the PKK to establish camps in northern Iraq.
PKK also establishes camps in Lebanon’s Bekaa Valley with the support of Syria.
Conflict Begins, Gulf War, and Initial U.S. Terrorist Designation (1984-1998)
In 1984, with Ocalan based in Syria, the PKK launched an armed insurgency in Turkey. Using guerrilla tactics, the PKK primarily targeted Turkish military and other state officials in largely Kurdish-populated southeastern Turkey. The group also sought to supplant the traditional Kurdish ruling class by attacking state-aligned “collaborationists.” The PKK insurgency reached its height in the mid-1990s; fighting since 1984 has killed thousands of PKK fighters,
Turkish security forces, and civilians. After the 1991 Gulf War, the PKK entrenched itself further in northern Iraq, prompting periodic Turkish military action.
1984 PKK begins armed insurgency in Turkey; Turkish government tightens security in southeast.
1985 Turkey establishes the Village Guards, a Kurdish paramilitary group to counter the PKK.
1987 KDP leader Barzani cuts ties with the PKK; PKK continues to use camps in northern Iraq and receives permission for some limited use of Iranian territory.
Turkey declares state of emergency in southeast.
1991 After the Gulf War, Iraqi forces brutally suppress an Iraqi Kurdish uprising, prompting mass refugee flows to Turkey and Iran; the United States and others provide relief from Turkey, and establish a no-fly zone to encourage refugees’ return.
1993 Conflict intensifies in southeastern Turkey.
1994 U.S. Congress enacts legislation withholding military loans to Turkey until the executive branch submits a report on alleged human rights violations related to Turkey-PKK violence.
1997 Turkey lifts state of emergency in part of its southeast.
State Department designates the PKK as a Foreign Terrorist Organization (FTO).
Turkish forces enter northern Iraq to support Barzani against his PKK-supported Iraqi Kurdish rivals.
1998 Facing Turkish military threats and other pressure, Syrian President Hafez al Asad expels Ocalan and closes PKK camps in line with an agreement known as the Adana Protocol.
Ocalan’s Capture, 2nd Iraq War, and Renewed Conflict (1999-2008)
Turkish authorities captured and imprisoned Abdullah Ocalan in 1999, ending one phase of Turkey-PKK conflict. After the U.S. invasion of Iraq in 2003, Iraq’s Kurdistan Regional Government (KRG) received formal autonomy. In 2004, the PKK restarted its insurgency, relying largely on the camps it had established in the 1980s in what had become KRG-controlled areas of northern Iraq. In response, Turkey increased its operations in Iraq.
1999 Ocalan, in prison, calls for PKK to declare a cease- fire and pull out of Turkey; PKK largely obeys.
2001 State Department designates PKK as a Specially Designated Global Terrorist.
2003 U.S. invasion of Iraq.
PYD (Democratic Union Party) is founded as PKK’s political offshoot in Syria.
Turkey (Türkiye), the PKK, and U.S. Involvement: Chronology
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2004 PKK insurgency resumes.
2005 Ocalan abandons call for independent Kurdish state and calls for Kurds to pursue “democratic confederalism” in their respective countries.
2007 The United States helps prevent a major Turkish cross-border intervention in Iraq by agreeing to share intelligence to help Turkey target PKK installations in mountainous areas of northern Iraq.
2008 President George W. Bush designates the PKK as Significant Foreign Narcotics Trafficker.
Peace Process and PYD/YPG Ascent in Syria (2009-2014)
Turkish Prime Minister Recep Tayyip Erdogan, who came to office in 2003 expressing some openness to greater freedoms for expressions of Kurdish identity, initiated a “solution process” that provided some rights for Turkish Kurds and raised hopes for a larger Turkey-PKK settlement. The war in Syria and the rise of both the Islamic State (IS/ISIS) and the PKK-linked YPG added new challenges to U.S.-Turkey relations. Erdogan was elected Turkey’s president in 2014.
2009 Turkey declares beginning of “solution process.”
2011 Syria conflict begins.
2012 Erdogan reveals secret government talks with Ocalan.
Syrian regime forces withdraw from most Kurdish- majority areas, effectively ceding control to the PYD and its YPG militias.
Turkish government engages in talks with PYD leaders in effort to distance PYD/YPG from PKK.
2014 YPG and PKK aid Iraqi Kurdish peshmerga in Iraq’s Sinjar against Islamic State; peshmerga gain Erdogan’s approval to transit through Turkey to aid YPG in IS- besieged Syrian border town of Kobane.
U.S. air operations against the Islamic State indirectly help the YPG and other anti-IS forces in Kobane area.
U.S.-YPG Cooperation and U.S.-Turkey Tensions over Syria (2015-2024)
The Turkey-PKK peace process broke down in August 2015 amid violence in Turkey apparently connected in some ways to conflict taking place in Syria. Soon thereafter, the YPG became the main U.S. counter-IS ground force partner in Syria (as the backbone of the Syrian Democratic Forces, SDF), receiving U.S. training and, since 2017, arms. Amid debate about how to continue countering the Islamic State, Turkey launched a major incursion against the YPG in Syria in 2019, contributing to a spike in U.S.-Turkey tensions. During the subsequent five-year standoff in Syria, Turkey (and allied Syrian armed groups) and the SDF (and affiliated groups) respectively administered different areas.
2015 With U.S. and coalition support, PYD/YPG and affiliated non-Kurdish militias (collectively known as the SDF) start reversing IS gains in northern Syria and establishing governing councils in areas they occupy.
June parliamentary elections: Erdogan’s party loses majority; Turkey’s Kurdish nationalist party achieves unprecedented success.
IS terrorist attacks target Kurds in Turkey.
Domestic Turkey-PKK clashes resume, especially in southeastern urban areas.
November parliamentary elections: Erdogan’s party regains majority; some fall-off in support for Kurdish party.
2016 Turkish authorities reestablish control in southeast, but significant human rights concerns persist.
Turkey, working with Syrian rebel partners, launches its first major ground campaign against IS-held territory, while also aiming to prevent further SDF gains.
2017 United States decides to directly arm YPG in advance of the campaign capturing Raqqa from the Islamic State, promising the recovery of YPG arms after IS’s defeat.
2018 Turkey-led forces push YPG-led forces (different from those connected with the U.S. military) out of Afrin, Syria; some counter-IS operations stop because of the diversion of some SDF personnel to Afrin.
State Department announces rewards for help that might lead to the capture of three senior PKK leaders.
2019 U.S. troops near the Turkey-Syria border are repositioned and Turkey launches incursion to push YPG forces from the border area. Trump Administration briefly imposes some sanctions on Turkey; House passes sanctions bill against Turkey.
Turkey arranges with the United States and Russia for the removal of YPG forces from “safe zones.”
2019- 2024
U.S.-SDF partnership continues outside of “safe zones,” including at various detention facilities or camps holding IS members or affiliated displaced persons. Occasional PKK attacks occur in Turkey, and the Turkish military continues operations against the PKK and its affiliates in Turkey, Syria, and Iraq.
Starting in fall 2024, Turkey’s governing coalition indicates a possible willingness to deal with Ocalan and other Kurdish leaders if they can remove PKK threats of violence against Turkey.
Asad’s Overthrow and Intensification of Turkey-SDF/YPG Rivalry (2024-Present)
With the Asad regime’s downfall and its replacement by a transitional government in Syria, Turkey-backed and SDF/YPG forces renewed fighting over contested areas of northern Syria in December 2024. Syrian de facto leader Ahmed al Sharaa has acknowledged Kurdish rights in Syria, but has called for an end to SDF military autonomy. U.S. officials have stated support for a cease-fire around Kobane and a “managed transition” regarding the SDF’s counter-IS role. Two Senators proposed sanctions against Turkey (S. 5643, 118th Congress) while calling on Turkish leaders to accept a cease-fire and demilitarized zone.
Jim Zanotti, Specialist in Middle Eastern Affairs Clayton Thomas, Specialist in Middle Eastern Affairs
IF11380
Turkey (Türkiye), the PKK, and U.S. Involvement: Chronology
https://crsreports.congress.gov | IF11380 · VERSION 2 · UPDATED
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