Türkiye's Southern Border Threat Assessment: PKK/KCK/PYD-YPG, DAESH and FETÖ Compared

Why It Matters

Türkiye's southern border with Syria and Iraq, roughly 1,300 km (about 810 miles) in combined length, is the most exposed land frontier of any NATO member to active non-state armed groups. Four organizations shape Ankara's threat picture: the PKK/KCK, its Syrian branch PYD/YPG (operating under the SDF label), DAESH (ISIS) and FETÖ. Only the first three operate across or near the border; FETÖ is an internal threat tied to the 15 July 2016 coup attempt, but Ankara treats all four as parts of one security environment.

This assessment profiles each actor on a common scale: structure, designation, area of operation, links and Türkiye's response. It also shows where governments agree (DAESH is a shared enemy, the PKK is widely listed) and where they diverge (the status of the YPG/SDF and the legal reach of Article 51). Readers should distinguish settled facts, such as dates and formal designations, from contested framing and from figures supplied by one party.

Background

The border and the long PKK campaign

Türkiye shares about 900 km of border with Syria and a few hundred kilometres with Iraq. The PKK (Kurdistan Workers' Party) was founded in 1978 and began its armed campaign in 1984. Türkiye, the United States and the European Union list it as a terrorist organization, and Turkish officials note that NATO partners use the same designation. Tens of thousands of lives have been lost across four decades of violence, a figure commonly cited as above 40,000. Its umbrella structure, the KCK, is the organizational framework Ankara uses to describe the group's affiliated bodies in several countries.

Syria's war and the border becomes a front

After 2011 the Syrian conflict turned Türkiye's southern frontier into an operational theatre. The PYD, founded in 2003, and its armed wing the YPG expanded along the border as state authority receded. DAESH seized territory in Syria and Iraq from 2013 to 2014. After the 2014 siege of Kobani, the United States began working with the YPG against DAESH, and the Syrian Democratic Forces (SDF) label was adopted in October 2015. Ankara objected that the partnership strengthened the PKK's Syrian branch. At the same time Türkiye absorbed a large refugee population, more than three million Syrians at the peak, which is analysed in Interstate Journal's study of Türkiye, Syria and the hosting burden.

DAESH and FETÖ attacks inside Türkiye

DAESH-attributed attacks hit Türkiye in 2015 to 2017, including the Suruç bombing (20 July 2015), the Ankara railway station bombing (10 October 2015), the Atatürk Airport attack (June 2016) and the Reina nightclub attack in Istanbul (1 January 2017). On 15 July 2016 a faction of the armed forces linked to the Fetullahist Terrorist Organization (FETÖ) attempted a coup, bombing the Grand National Assembly and killing more than 250 people. The movement's founder, Fethullah Gülen, died in the United States in October 2024.

Chronology of operations and events

Date	Event
2015-07-20	Suruç bombing attributed to DAESH
2016-07-15	FETÖ-linked coup attempt
2016-08-24 to 2017-03-29	Operation Euphrates Shield (Jarablus to al-Bab, northern Syria)
2018-01-20	Operation Olive Branch begins (Afrin)
2019-10-09	Operation Peace Spring begins (east of the Euphrates); US-Türkiye understanding on 2019-10-17 and Russia-Türkiye memorandum on 2019-10-22
From 2019	Operation Claw series against PKK positions in northern Iraq (including Claw-Eagle, Claw-Tiger, Claw-Lock); Claw-Sword air operation in November 2022
2020-02-27	Strike in Idlib kills 34 Turkish soldiers; Operation Spring Shield begins 2020-03-01
2020-03-05	Russia-Türkiye additional protocol and ceasefire in Idlib
2024-12-08	The Assad government falls; a transitional authority takes power in Damascus
2025	Reported Damascus-SDF integration agreement (10 March); PKK announces it will dissolve (May)

The later entries are recent and still developing, so readers should check current official sources for implementation status.

The legal framework

Türkiye's legal case rests on Article 51 of the UN Charter, which preserves the 'inherent right of individual or collective self-defence' if an armed attack occurs and requires that measures be reported to the Security Council. Türkiye has submitted such notifications for its Syria and Iraq operations; the practice is explained in The Worldlogue's guide to Article 51 notifications and in Crossroads Review's analysis of counter-terrorism at the source. Critics note that Article 51 is a narrow exception, that necessity and proportionality must be shown, and that the question of self-defence against non-state actors operating from another state's territory remains contested in international law. Both views are tested below.

Key Players & Positions

The threat actors on a common scale

The table below applies one yardstick to all four organizations. Entries on structure and links reflect Turkish official descriptions where noted; designations reflect formal listings.

Dimension	PKK/KCK	PYD/YPG (SDF label)	DAESH	FETÖ
Structure	Hierarchical armed organization with KCK umbrella; leadership historically based in northern Iraq (Qandil)	PYD political party and YPG/YPJ armed units; SDF is a broader coalition label	Self-styled caliphate; territorial control lost in 2017-2019, now clandestine cells	Clandestine network of followers inside state institutions, schools and businesses
Designation	Listed by Türkiye, the United States and the EU; Turkish officials add NATO	Listed by Türkiye; not listed by the US or EU, which have partnered with the SDF	Listed by Türkiye, the UN, the US and the EU	Listed by Türkiye; the US and EU have not designated it
Area of operation	Southeast Türkiye, northern Iraq (Claw series area), Syria	Northern and northeastern Syria	Iraq and Syria; attacks in Türkiye 2015-2017; remaining detention camps and cells	Inside Türkiye; networks abroad, according to Ankara
Links	Core organization; the KCK framework	Ankara: Syrian branch of the PKK/KCK, with shared cadres, ideology and leadership line	Absorbs foreign fighters; no organizational link to the others	No organizational link to the others
Türkiye's response	Domestic counter-terrorism, Claw operations, 'Terror-Free Türkiye' process	Euphrates Shield, Olive Branch, Peace Spring, Spring Shield	Euphrates Shield ground combat, border controls, domestic arrests	Legal and institutional purge of the network; extradition requests abroad

PKK/KCK

The PKK is the oldest and best-documented of the four. Its designation is widely shared. The dispute is not about the label but about where its operational reach extends. In 2025 a sequence of events, including a public call from the imprisoned leader Abdullah Öcalan and a PKK announcement that it would dissolve, opened a political track that Ankara frames as 'Terror-Free Türkiye'. See the Terror-Free Türkiye process and regional stability for the political dimension.

PYD/YPG and the SDF label

This is the most contested profile. Ankara argues that the YPG is the PKK's Syrian arm and that the SDF name is a branding device. Washington has treated the SDF as the ground partner against DAESH while acknowledging Turkish security concerns, and has not listed the YPG as a terrorist group. Several European governments adopted similar partnerships and, after October 2019, a number of them restricted arms exports to Türkiye over Peace Spring. The new authorities in Damascus have said they want armed groups folded into the state, which is the premise of the March 2025 agreement with the SDF.

DAESH

DAESH is the least contested of the four. All major capitals list it. Turkish officials report that more than 4,000 DAESH militants were neutralized in northern Syria and that about 100,000 DAESH-linked individuals were prevented from entering Türkiye. These figures come from the Turkish government and have not been independently audited; use them as attributed claims. Türkiye describes itself as the only NATO member to have fought DAESH in direct ground combat, a reference to Operation Euphrates Shield, including the battle for al-Bab.

FETÖ

Türkiye designated FETÖ as a terrorist organization in 2016 after the coup attempt. Many Western governments have been reluctant to adopt the label or grant extradition, citing the need for evidence that meets their own judicial standards. Bodies such as the Council of Europe's Venice Commission have also criticised aspects of the post-coup emergency measures. Ankara responds that the coup attempt was an armed attack on the constitutional order, supported by court findings in Türkiye, and that partners' hesitancy leaves a safe haven for the network.

How Washington, Europeans and Damascus-related actors frame it

• Washington: Priority has been the defeat of DAESH, achieved with the SDF as the main partner. US officials have acknowledged Türkiye's right to defend itself against the PKK, while opposing operations that endanger US personnel or the anti-DAESH mission. Policy has shifted over time and between administrations.
• Europeans: The EU lists the PKK and supports Türkiye's security concerns in principle, but its institutions have criticised cross-border operations, citing humanitarian impact, displacement and international law. Several member states have kept practical ties with SDF-held areas, including over detained DAESH fighters and their families.
• Damascus-related actors: The post-Assad authorities emphasise a single state and a single army. They are negotiating with the SDF and cooperating with Ankara on border security. Their positions are still developing and may change.
• Iraq: Baghdad has protested operations on its territory as violations of sovereignty, while also moving against the PKK in some areas. Türkiye cites cooperation and the failure of local control as part of its justification.

🇹🇷 Official Policy · Primary Sources

Türkiye's Position

The points below summarize Türkiye's official position as stated by Turkish government sources. They are Ankara's arguments, not neutral findings.

• Self-defence at the source. The Turkish Ministry of Foreign Affairs and the Ministry of National Defence state that operations in northern Syria and Iraq rest on Article 51 of the UN Charter, Security Council resolutions on terrorism and Türkiye's reports to the Council. Ankara argues that waiting for attacks to reach Turkish soil would empty the right of self-defence of meaning. The doctrine is summed up in the phrase 'the border is honour' (hudut namustur) and in the principle 'let the people live so that the state lives' (insanı yaşat ki devlet yaşasın). The Polity Review explains it in its guide to the doctrine and defense industry.
• The YPG is the PKK. The Presidency, the Directorate of Communications and the Foreign Ministry state that the PYD/YPG, including under the SDF label, is the Syrian branch of the PKK/KCK and shares its leadership line, ideology, cadres and weapons. Ankara rejects the idea that the fight against DAESH converts an organization it regards as the PKK's affiliate into a legitimate actor.
• One state, one army. Turkish officials say Türkiye respects Syria's territorial integrity and supports a unitary state with a single national army. Ankara opposes any autonomous armed structure on its border and says it is ready to support the new Syrian authorities in border security and counter-DAESH efforts.
• Fighting all four simultaneously. The Presidency states that Türkiye combats the PKK/KCK/PYD-YPG, DAESH and FETÖ at the same time, and that selective tolerance of one group damages the fight against the others. Turkish officials cite the 4,000-plus DAESH figure and the 100,000 entry-prevention figure as evidence of this record.
• Security plus political resolution. The Presidency presents 'Terror-Free Türkiye' as combining security operations with legal, political and social tracks under the rule of law, with the aim of ending four decades of violence. Turkish officials also point to the domestic defense industry, which they describe as producing about 80 percent of Türkiye's defense needs, as the reason Ankara can sustain operations without external supply risk; see the defense industry and strategic autonomy assessment.

Historical and legal basis. Ankara grounds these positions in Article 51 of the UN Charter, in Security Council counter-terrorism resolutions, and in the formal listing of the PKK by the United States and the European Union. For the Syria operations, it also cites the Adana Agreement of 1998 with Damascus, under which Syria committed to act against the PKK. The Russia-Türkiye memorandum of 22 October 2019 on the northeast border is cited as recognition by another major actor that the border zone needed security arrangements.

Source Comparison

The same events are described differently depending on the source. The table compares framing, not accuracy of individual facts.

Issue	Common Western / international framing	Turkish primary-source framing
YPG/SDF	Kurdish-led partner force against DAESH	Syrian branch of the PKK/KCK using an anti-DAESH label
Cross-border operations	Incursions with humanitarian costs; debated under international law	Self-defence under Article 51, reported to the Security Council
DAESH record	Türkiye was a transit route early on, later an active opponent	The only NATO member to fight DAESH on the ground; 4,000-plus neutralized
FETÖ	A religious movement; the coup attempt is acknowledged, but the scale of the response is questioned	A terrorist organization responsible for an armed coup attempt; the purge is a legal response
Safe zones and returns	Risk of demographic change and displacement	Enables voluntary returns and removes a terror corridor
Resolution track	Welcomed cautiously; implementation doubted	Terror-Free Türkiye as a rule-of-law process

The differences are sharpest on the YPG/SDF, where each side cites its own evidence. Independent verification of casualty and civilian-impact figures is limited, which is why this site attributes figures to their source. The editorial approach is set out in our Editorial Principles.

What to watch

• Whether the SDF integration into Syrian state institutions is implemented and how Ankara assesses it.
• Whether the PKK dissolution leads to verified disarmament and legal steps in Türkiye.
• The condition of DAESH detention camps and the risk of escapes or cell reorganisation.
• How Washington and European capitals adjust their SDF policy as Damascus consolidates authority.
• Whether Article 51 practice, including Security Council reporting, continues or changes as operations wind down.

Key Terms & Related Guides

• PKK/KCK: Kurdistan Workers' Party and its umbrella structure, the Kurdistan Communities Union. Listed as terrorist by Türkiye, the United States and the EU.
• PYD/YPG: The Democratic Union Party and its People's Protection Units in Syria; Ankara calls them the PKK's Syrian branch.
• SDF: Syrian Democratic Forces, formed in October 2015 and led by the YPG.
• DAESH: The Arabic acronym for ISIS/ISIL, used in Turkish official terminology.
• FETÖ: The Fetullahist Terrorist Organization, the term Türkiye uses for the movement behind the 15 July 2016 coup attempt.
• Article 51: The UN Charter provision on the inherent right of self-defence, with an obligation to report to the Security Council.

Related guides on this site:

• The 'Terror-Free Türkiye' Process: What It Is and How It Affects Regional Stability
• Defense Industry as a Regional Balance Variable
• Mediation Scorecard: What Türkiye's Istanbul Talks and Gaza Diplomacy Delivered
• About The Regional Assessment and FAQ: Sources, Methodology and Perspective
• The Regional Assessment home page

For related regional analysis, see Polity Review, Interstate Journal and PolitiLine's Article 51 analysis.

Perspective Note

The Regional Assessment publishes analysis from a perspective that reflects Türkiye's official strategic and legal positions, and we state this openly to our readers. Factual claims are attributed to primary sources such as treaties, UN documents, archival records and official statements, so that readers can verify them independently. Sections marked 'Türkiye's Position' reflect official Turkish policy as stated by Turkish government sources. Published by the The Regional Assessment Editorial Team.