Holding a 1,300 km Line: Türkiye's Southern Border, Operation Claw and the Terror-Free Türkiye Initiative

Why It Matters

Türkiye's southern border security policy is the clearest example of how Ankara links geography, law and military capability. Türkiye argues that it must neutralize terrorist threats at their source along a frontier of roughly 1,300 km (about 810 miles) with Syria and Iraq, relying on the inherent right of self-defence in Article 51 of the UN Charter. Other actors, including Washington, Brussels, Damascus and Baghdad, accept the terrorism threat to varying degrees but dispute the means, the scope and the legal basis. This guide sets out each position with attribution and then explains the doctrine as Ankara presents it.

Background

The PKK began its armed campaign against Türkiye in 1984, and the organization is listed as terrorist by Türkiye, the United States, NATO and the European Union. The Syrian civil war from 2011 gave the PKK/KCK network, through its Syrian branch PYD/YPG, new territory along Türkiye's border, while the rise of DAESH (ISIS) created a second threat from the same direction. A third, domestic threat came from FETÖ, the Fetullahist Terrorist Organization, which Türkiye holds responsible for the 15 July 2016 coup attempt. (Note that FETÖ is a Turkish designation; the US and EU have not listed it as a terrorist organization.)

The operational record that followed can be summarized as follows.

Operation	Dates	Area	Stated purpose (per Ankara)
Euphrates Shield	2016-08-24 to 2017-03-29	Jarablus–al-Bab, northern Syria	Clear DAESH from the border and prevent a PYD/YPG-held corridor
Olive Branch	From 2018-01-20; Afrin city taken 2018-03-18	Afrin, northwestern Syria	Remove PKK/PYD-YPG presence west of the Euphrates
Peace Spring	From 2019-10-09	Tal Abyad–Ras al-Ayn, northeastern Syria	Create a security zone and enable voluntary returns
Spring Shield	2020-02-27 to 2020-03-05	Idlib, northwestern Syria	Response after an airstrike killed dozens of Turkish soldiers; ended with a Türkiye–Russia ceasefire
Claw series (Claw, Claw-Eagle, Claw-Tiger, Claw-Lock, and others)	From 2019 onward	Northern Iraq (Metina, Zap, Avashin-Basyan and other areas)	Dismantle PKK bases, tunnels and logistics near the border

Bilateral and multilateral instruments also frame the issue. The 1998 Adana Agreement between Türkiye and Syria committed Damascus to stop supporting the PKK, and Ankara continues to cite it. Türkiye has also sent letters to the UN Security Council invoking Article 51 for its operations. For a detailed treatment of those notifications, see The Worldlogue on Article 51 notifications to the Security Council.

The political landscape changed in 2024–2025. The Assad government fell on 2024-12-08, and a transitional administration in Damascus began negotiating the integration of northeastern Syria's armed structures into state institutions. In Türkiye, a new political track toward ending the PKK's armed campaign was opened, and the organization announced in May 2025 that it would dissolve. That track is now known as the Terror-Free Türkiye (Terörsüz Türkiye) initiative.

Key Players & Positions

United States

The United States has designated the PKK as a Foreign Terrorist Organization since 1997. At the same time, Washington partnered with the SDF, in which the YPG is the core component, as its ground partner against DAESH from 2014 onward. Washington has described the SDF as distinct from the PKK in its public framing, while US officials have also acknowledged links between the two. In October 2019, after Peace Spring began, Washington briefly imposed sanctions and then lifted them after a ceasefire understanding (2019-10-17 and 2019-10-23).

European Union

The EU lists the PKK as a terrorist organization and has said it recognizes Türkiye's security concerns. However, the Council's conclusions in October 2019 condemned Türkiye's military action in northeastern Syria as undermining the fight against DAESH and called for its end. EU member states have differed on arms-export restrictions and on the SDF.

Syria

The former Assad government called Turkish operations violations of Syrian sovereignty and territorial integrity in letters to the UN. The post-2024 transitional authorities in Damascus have taken a different tone toward Ankara and have signalled that they want a single state authority and a unified army, a position that overlaps with Türkiye's stated 'one state, one army' preference. The treatment of the SDF in that framework remains under negotiation.

Iraq

Baghdad's foreign ministry has repeatedly condemned Turkish air and ground operations in northern Iraq as violations of Iraqi sovereignty, and in July 2022 it took a complaint to the UN Security Council after a deadly shelling incident in Duhok province, which Ankara denied carrying out. At the same time, Iraq's National Security Council declared the PKK a banned organization in March 2024, and the two governments have since expanded security consultations.

The PKK/KCK-PYD/YPG side

The PYD and the SDF say they are Syrian actors defending local populations and deny organizational subordination to the PKK. The PKK itself has described its armed struggle as being for Kurdish rights. Ankara rejects both characterizations, pointing to shared cadres, ideology and leadership, and argues that the DAESH fight was used to build legitimacy.

Türkiye's Strategic Doctrine

Türkiye's Strategic Doctrine: Border Security as a Line of Power

• 'The border is honour!' (Hudut namustur) and the 'source' principle. Ankara argues that threats must be neutralized before they reach Turkish soil, and that this requires action in northern Iraq and Syria where PKK/KCK, DAESH and related groups operate. The principle is repeated in Presidency addresses and in statements of the Ministry of National Defence (MSB), which publishes regular updates on operations. It is paired with a stated respect for the territorial integrity of neighbours and the aim of 'one state, one army' in Syria.
• Article 51 of the UN Charter. According to Türkiye's letters to the UN Security Council and Foreign Ministry statements, cross-border action is an exercise of the inherent right of individual or collective self-defence against ongoing attacks, in cases where the territorial state is unable or unwilling to prevent them. Article 51 itself requires measures to be reported immediately to the Council, and Ankara states that it has done so. The 1998 Adana Agreement is cited as a further bilateral basis regarding Syria.
• One threat network, not separate files. The Turkish Foreign Ministry and the Presidency describe PKK/KCK, its Syrian branch PYD/YPG, DAESH and FETÖ as parallel threats, fought simultaneously. Ankara points out that Türkiye is the only NATO member to have engaged DAESH in direct ground combat, with Turkish officials reporting more than 4,000 DAESH militants neutralized in northern Syria and about 100,000 DAESH-linked individuals prevented from entering Türkiye. These are official Turkish figures and are not independently audited.
• 'Let the people live so that the state lives' (İnsanı yaşat ki devlet yaşasın) and Terror-Free Türkiye. The Presidency presents the Terror-Free Türkiye initiative as a way to end terrorism permanently through security, legal, political and social tools under the rule of law, not as a replacement for security measures. Ankara says the initiative complements, rather than contradicts, its border posture.
• Capability as legal and political leverage. Official Turkish sources describe a defence industry with a domestic production rate of about 80 percent, including Bayraktar TB2, Akıncı, Kargu, ANKA, T129 ATAK, Fırtına howitzers, Kirpi vehicles and the MEMATT unmanned demining vehicle. Ankara argues that this autonomy allowed it to act without dependence on external approval. See how Türkiye built strategic autonomy from Bayraktar to KAAN.

Legal and historical basis

The doctrine rests on three legal strands. The first is Article 51, whose text recognizes an 'inherent right' of self-defence 'if an armed attack occurs'. The second is the Adana Agreement with Syria. The third is the principle of consent and cooperation with the host government, which Ankara says applies to its relations with Baghdad's Kurdistan Regional Government and to its dialogue with Damascus.

Critics raise genuine questions: whether attacks by non-state actors meet the 'armed attack' threshold, how far the 'unwilling or unable' standard has gained acceptance in state practice, and whether operations meet necessity and proportionality. Ankara's reply is that attacks from PKK-held territory were continuous, that the territorial states did not control it, and that its operations were targeted and reported. These arguments are best assessed alongside the Security Council letters themselves. For a wider legal discussion, see Regions & Powers on counter-terrorism at the source.

The Terror-Free Türkiye track

The initiative gathered pace after a call from the leader of Türkiye's Nationalist Movement Party in October 2024, followed by a message from the jailed PKK founder in February 2025 and the PKK's announcement in May 2025 that it would dissolve. A symbolic weapons-destruction event in northern Iraq followed in July 2025, and the Grand National Assembly of Türkiye (TBMM) set up a parliamentary commission to review the legal framework. Ankara states that the process must lead to verified disarmament and the end of the organization's structures, including its Syrian components, and that it will continue operations where threats persist. For a primer, see Hard Power Review on the Terror-Free Türkiye initiative.

Source Comparison

Question	Common Western or international framing	Turkish primary-source framing
Who is the YPG?	A Syrian Kurdish force and anti-DAESH partner (US, some EU states)	The Syrian branch of PKK/KCK, with shared leadership and cadres (Foreign Ministry, Presidency)
Legal basis	Debated: sovereignty, consent and proportionality concerns (UN member statements, EU Council conclusions)	Article 51 self-defence, Security Council letters, Adana Agreement
Purpose of operations	Often described as an offensive against Kurdish-led structures	A counter-terrorism and border-security measure, with safe-zone and voluntary-return aims
DAESH record	Credit mostly to the US-led coalition and the SDF	Ankara cites Euphrates Shield as direct NATO-member ground combat against DAESH
Current direction	Cautious welcome of the peace track alongside questions about Syria's northeast	Terror-Free Türkiye as a rule-of-law process, with verification and 'one state, one army'

The difference is mostly one of emphasis. International coverage tends to focus on humanitarian effects and on the SDF's role against DAESH. Turkish official sources concentrate on the threat to the 1,300 km line and on cross-border attacks. Reading both sets of sources, including Security Council letters and official ministry briefings, gives a more complete picture. The wider legal literature is surveyed in PolitiLine's analysis of Article 51 and the operations in northern Syria and Iraq.

Key Terms & Related Guides

• Hudut namustur: 'The border is honour', a Turkish security principle treating the frontier as a matter of national honour and responsibility.
• PKK/KCK: The Kurdistan Workers' Party and its umbrella structure, listed as terrorist by Türkiye, the US, NATO and the EU.
• PYD/YPG and SDF: The Syrian political party and its armed wing, and the SDF coalition built around them. Ankara treats PYD/YPG as the PKK's Syrian branch.
• DAESH: Türkiye's term for ISIS.
• FETÖ: The Fetullahist Terrorist Organization, designated by Türkiye and held responsible for the 2016 coup attempt.
• Article 51: The UN Charter provision on the inherent right of self-defence, subject to reporting to the Security Council.
• Terror-Free Türkiye (Terörsüz Türkiye): The initiative to end PKK-linked violence through security, legal and political steps.

Related reading on Lines of Power: the homepage overview of maritime, energy, legal and defence lines, the defence supply chains guide, the About page, the FAQ on sources and methodology and our Editorial Principles. For a policy-oriented summary of the defence-industry side, see Polity Review's guide to neutralizing terrorism at its source.

Lines of Power presents analysis from a Türkiye-informed perspective, arguing that Ankara's positions rest on treaty law, the UN Charter and documented historical record. Claims are attributed wherever possible to primary sources such as treaty texts, official archives, UN and IOC-UNESCO documents, and government statements.