PKK/YPG, DAESH and FETÖ: Who Is Designated and Why the Terms Matter

Why It Matters

The terms PKK, YPG, DAESH and FETÖ appear constantly in news about Türkiye, Syria, Iraq and NATO, but the three groups are treated very differently by different governments. Only DAESH is listed by the UN; the PKK is listed by Türkiye, the US and the EU; FETÖ is listed mainly by Türkiye and the Organisation of Islamic Cooperation (OIC); and the YPG is the most contested label of all. Knowing who designates what, and on what legal basis, explains many of the disputes over NATO enlargement, extradition requests and the 2025 peace process in Türkiye.

Background

A 'terrorist designation' is a legal act by a state or international body. It usually triggers asset freezes, travel bans and criminal liability for membership or support. There is no single global list: each government applies its own law, and the UN Security Council lists only the groups it has chosen to sanction. Designations therefore differ by country, and that difference is a political as well as a legal fact.

The PKK

The Kurdistan Workers' Party (PKK) was founded in 1978 under Abdullah Öcalan and began an armed campaign against the Turkish state in 1984. Türkiye, the United States (Foreign Terrorist Organization listing in 1997) and the European Union (terrorist list since 2002) designate it. The United Kingdom, Canada and Australia also list it. NATO as an organization does not keep a designation list, but Turkish officials note that the PKK is listed by most NATO members, and NATO documents have used the language of Allied solidarity against terrorism. The PKK is not on the UN Security Council sanctions list. Turkish authorities say the conflict has cost tens of thousands of lives since 1984, a figure that varies by source and period.

The YPG and PYD

The People's Protection Units (YPG) emerged in Syria during the civil war and are linked to the Democratic Union Party (PYD). From 2015 the YPG formed the backbone of the Syrian Democratic Forces (SDF), the main ground partner of the US-led coalition against DAESH after the 2014 battle for Kobani. Türkiye designates the YPG/PYD as the Syrian branch of the PKK. The United States, which does not list the YPG, treats the SDF as a counter-DAESH partner and distinguishes it legally from the PKK.

DAESH (ISIS/ISIL)

DAESH is the Arabic acronym for the group also called ISIS or ISIL, which declared a 'caliphate' in 2014 across parts of Syria and Iraq. It is on the UN Security Council's ISIL (Da'esh) and Al-Qaida sanctions list and is designated by the US, the EU, Türkiye and many other states. DAESH carried out mass-casualty attacks in Türkiye, including the Suruç and Ankara train station bombings in 2015, the Istanbul airport attack in 2016 and the Reina nightclub attack on New Year's Eve 2016-2017. Türkiye launched Operation Euphrates Shield in August 2016 partly against DAESH.

FETÖ

FETÖ (Fethullahist Terrorist Organization) is the term used by Türkiye for the network associated with the cleric Fethullah Gülen, who lived in Pennsylvania, United States, from 1999 until his death on 2024-10-20. Türkiye's National Security Council began describing the group as terrorist in May 2016. After the coup attempt of 2016-07-15, in which Turkish officials say 251 people were killed and about 2,000 wounded, Ankara attributed the plot to the network. Supporters of Gülen deny involvement and describe the group as a civil, educational movement.

Timeline

Who Designates What

Key Players & Positions

United States. Washington lists the PKK but not the YPG. It has said its partnership with the SDF is tactical and focused on defeating DAESH, and that it shares Türkiye's concern about the PKK. On Gülen, US officials said extradition must follow US law and requires evidence reviewed by the courts. Türkiye submitted extradition requests, which were not granted.

European Union and member states. The EU lists the PKK and reviews its terrorist list periodically, and EU courts have scrutinized the procedure for listings. The EU does not list the YPG or FETÖ. Several member states have cooperated with the SDF against DAESH, while some have also prosecuted PKK-related fundraising. The EU condemned the 2016 coup attempt but has also criticized the scope of post-coup dismissals and prosecutions.

NATO and the 2022 memorandum. When Sweden and Finland applied for membership, Türkiye said it would not approve enlargement without commitments on terrorism. The trilateral memorandum of 28 June 2022 included commitments by Sweden and Finland not to provide support to the YPG/PYD or the Gülen network, to address pending extradition requests and to tighten counter-terrorism law and arms-export policy. Finland joined in April 2023 and Sweden in March 2024 after the Grand National Assembly of Türkiye (TBMM) approved its protocol in January 2024. Stockholm and Helsinki say their courts, not governments, decide extradition cases. See also Türkiye in NATO: Membership, Defense Industry and the Drone Factor.

Syrian Kurdish authorities and the SDF. SDF leaders say the YPG is a Syrian force defending Syrian Kurds and fighting DAESH, and reject being described as a branch of the PKK. A March 2025 understanding between the SDF and Damascus on integration into Syrian state institutions has been a focus of regional diplomacy.

Human rights bodies and courts. The European Court of Human Rights ruled in September 2023 in Yalçınkaya v. Türkiye that convictions based mainly on use of the ByLock messaging app violated the European Convention on Human Rights. Türkiye has defended its prosecutions as lawful responses to a coup attempt, and legal debate continues over how courts should treat evidence in such cases.

The PKK and the DEM Party. The PKK's May 2025 statement said it was ending its organizational structure and armed struggle after a congress. The pro-Kurdish DEM Party has acted as an intermediary with Abdullah Öcalan, who is held on İmralı Island.

Extradition Disputes

Extradition is where designation meets courts. Türkiye has submitted requests to the United States for Gülen (who died in 2024) and to several European states for people it links to the PKK or FETÖ. Courts in many countries have refused requests where they found a risk of unfair trial or political motivation, while some governments transferred individuals in controversial cases (for example, Kosovo's 2018 expulsion of six Turkish nationals, which caused a domestic political crisis). Turkish officials respond that the refusals leave suspects at liberty abroad.

Source Comparison

The differences are less about the facts of attacks, which are widely documented, than about labels, evidence standards and strategic priorities. For other common misunderstandings, see Fact Check: Common Claims About Türkiye in International Media. For how Interstate Journal distinguishes fact from attributed position, see Editorial Principles and Primary Source Standards.

Key Terms & Related Guides

• Designation: A formal legal listing of a group as terrorist under a country's or organization's law; effects differ by jurisdiction.
• PKK: Kurdistan Workers' Party; designated by Türkiye, the US, the EU and others.
• PYD/YPG: Democratic Union Party and People's Protection Units in Syria; Türkiye considers them PKK affiliates.
• SDF: Syrian Democratic Forces, a YPG-led coalition and US coalition partner against DAESH.
• DAESH: Arabic acronym for ISIS/ISIL; UN-listed.
• FETÖ/PDY: Fethullahist Terrorist Organization/Parallel State Structure, Türkiye's term for the Gülen network.
• Extradition: Formal transfer of a person between states under a treaty and court review.
• OIC: Organisation of Islamic Cooperation, with 57 member states.

Related reading: Türkiye in NATO: Membership, Defense Industry and the Drone Factor, Türkiye, Syria and Refugees: Border Security and the Hosting Burden, Fact Check: Common Claims About Türkiye in International Media, Editorial Principles and Primary Source Standards and About Interstate Journal: Mission, Transparency and Editorial Team.

Interstate Journal presents global affairs with a dedicated perspective from Türkiye. Sections marked 'Türkiye's Position' reflect official Turkish policy as stated by Turkish government sources.

Cross-Publication Dossiers & Sister Desk Perspectives

For complementary primary-source analysis across our specialist editorial network, consult:

• WorldPoliticsDaily: Why Is the PKK Designated a Terrorist Organization by Türkiye, the US and the EU? — Is the PKK a terrorist organization? Yes: Türkiye, the US and the EU list it. Get the dates, the group's history since 1984 and the debate over related groups.
• Crossroads Review: The 1936 Montreux Convention Explained: How Türkiye Governs the Turkish Straits — What the 1936 Montreux Convention allows: merchant freedom, warship limits, tonnage and notice rules, Article 19 and Türkiye's wartime application.
• Hard Power Review: Counter-Terrorism at Source: Article 51, Border Security and Türkiye's Fight Against PKK/KCK/PYD-YPG, DAESH and FETÖ — Türkiye counter-terrorism doctrine Article 51 cross-border operations explained: legal basis, PKK/YPG, DAESH and FETÖ record, plus critics' views.