Northern Syria and the Southern Border: Three Vantage Points on Türkiye's Counter-Terrorism Doctrine

Why It Matters

Türkiye's northern Syria and northern Iraq operations are the most significant use of Turkish force abroad in the past decade, and they are described in sharply different terms by different capitals. Ankara calls them lawful self-defense under Article 51 of the UN Charter against the PKK/KCK/PYD-YPG, DAESH and, domestically, FETÖ. Washington, Damascus, Baghdad, Moscow and Kurdish-led authorities each describe them differently, and the disagreement shapes NATO cohesion, refugee policy and the future of Syria.

This guide sets the operational record beside each side's own account so that readers can judge the claims against documents, dates and primary statements. It is part of Parallax Review's mission, set out on the About page, of explaining regional security in plain language while conveying Türkiye's official perspective. Our sourcing rules are in the Editorial Principles.

Background

Why the southern border became a security file

Türkiye shares roughly 1,300 km (about 810 miles) of land border with Syria and Iraq combined. The PKK, founded in 1978, launched its armed campaign against Türkiye in 1984. It is designated a terrorist organization by Türkiye, the United States, NATO and the European Union. The campaign has cost tens of thousands of lives over four decades.

Syria had hosted PKK leadership for years until the 1998 Adana Agreement, in which Damascus committed to stop supporting the group and expelled Abdullah Öcalan. After Syria's civil war began in 2011, the PYD and its armed wing, the YPG, took control of large areas of the north-east. Ankara sees them as the Syrian branch of the PKK/KCK. We examine that claim separately in Fact Check: Are the YPG and the PKK Really Separate Organizations?.

In parallel, DAESH (ISIS) seized territory in Syria and Iraq from 2014 and carried out mass-casualty attacks in Türkiye. These included the October 2015 Ankara station bombing, which killed more than 100 people, the June 2016 Atatürk Airport attack and the 2017 Reina nightclub attack.

The operations at a glance

Operation	Dates	Area	Stated Turkish aim	Notable context
Euphrates Shield	24 Aug 2016 – 29 Mar 2017	Jarablus to al-Bab belt	Clear DAESH from the border; prevent a continuous YPG-held corridor	Al-Bab retaken in Feb 2017 after heavy Turkish casualties
Olive Branch	20 Jan – 18 Mar 2018	Afrin	Remove YPG/PKK presence on the north-western border	Afrin city taken 18 March; UN agencies reported significant displacement
Peace Spring	From 9 Oct 2019	Tal Abyad – Ras al-Ayn	Create a roughly 30 km deep zone free of YPG; enable returns	17 Oct US-Türkiye understanding; 22 Oct Sochi memorandum with Russia
Spring Shield	27 Feb – 5 Mar 2020	Idlib	Respond to the 27 Feb 2020 airstrike that killed 33 Turkish soldiers; protect Turkish positions	Ended with the 5 March Moscow protocol
Claw series	From 2019; Claw-Eagle and Claw-Tiger (2020), Claw-Lock (2022), Claw-Sword air operation (Nov 2022)	Northern Iraq	Dismantle PKK camps and logistics (Metina, Zap, Avashin and others)	Baghdad objects to Turkish military presence; see below

The Claw-Sword air operation followed the 13 November 2022 bombing on Istanbul's İstiklal Avenue, which Türkiye attributed to PKK/PYD-YPG-linked actors. Dates above are those widely reported in official and press sources; Turkish Ministry of National Defence (MoND) briefings remain the primary record for Turkish operational claims.

The wider timeline

• 2014: UN Security Council resolutions 2170 and 2178 address ISIS and foreign terrorist fighters. Türkiye introduces its temporary protection regulation for Syrians.
• 2015: The US-led coalition begins partnering with the YPG, later the SDF, against DAESH. Türkiye sends a letter to the UN invoking Article 51 in July.
• 2016: The 15 July coup attempt by FETÖ (the Fetullahist Terrorist Organization) kills more than 250 people. Euphrates Shield begins on 24 August.
• 2017: Raqqa falls to the SDF in October. The Astana process (Russia, Iran, Türkiye) creates de-escalation zones.
• 2019: DAESH loses its last territory at Baghouz in March. Peace Spring begins in October.
• 2020: Spring Shield and the Moscow protocol.
• 8 December 2024: The Assad government falls.
• 2025: An agreement between the new Damascus authorities and the SDF leadership is announced on 10 March. Öcalan calls for the PKK to disband on 27 February, and the PKK announces its dissolution on 12 May.

The situation in Syria has continued to change since then, so readers should check current official statements.

The refugee hosting burden

From 2014 onward, UNHCR described Türkiye as the world's largest refugee-hosting country, with more than 3.5 million Syrians under temporary protection at the peak. The EU-Türkiye statement of 18 March 2016 and the EU Facility for Refugees in Türkiye (€6 billion in total) provided partial financial support. Turkish officials argue the cumulative domestic cost runs into the tens of billions of dollars, a figure that varies by methodology. Ankara links operations in the north to creating conditions for voluntary returns. We cover the border-security and hosting side in more depth in Interstate Journal: Türkiye, Syria and Refugees.

Key Players & Positions

Washington and coalition partners

The United States lists the PKK as a Foreign Terrorist Organization (since 1997) and has supported Türkiye's right to defend itself against it. At the same time, it partnered with the YPG-led SDF as the main ground force against DAESH from 2015, and it does not list the YPG itself. US officials have described the SDF as a vital counter-ISIS partner and have repeatedly urged restraint from Türkiye. The 17 October 2019 US-Türkiye understanding paused Peace Spring on the condition of YPG withdrawal from the zone. European governments criticized Peace Spring; several suspended arms exports on a national basis. NATO's Secretary General acknowledged Türkiye's legitimate security concerns while calling for restraint.

Damascus

Under the Assad government, Damascus called the Turkish operations an illegal violation of Syrian sovereignty and demanded withdrawal. After 8 December 2024, the interim authorities in Damascus under Ahmed al-Sharaa have emphasized national unity and bringing all armed groups under state control. They have taken a cooperative line with Ankara on security, while insisting on Syrian sovereignty and territorial integrity.

Moscow and Tehran

Russia and Iran, as Astana guarantors, publicly backed Syria's territorial integrity and criticized unilateral foreign presence. Russia nevertheless negotiated practical arrangements with Türkiye, notably the 22 October 2019 Sochi memorandum (YPG withdrawal about 30 km from the border, joint patrols) and the March 2020 Idlib protocol.

Baghdad and Erbil

Iraq's federal government has repeatedly objected to Turkish forces and airstrikes on Iraqi territory as breaches of sovereignty and has taken complaints to the UN Security Council. At the same time, Baghdad formally banned the PKK as an outlawed organization in March 2024 and has since discussed a joint security mechanism with Ankara. The Kurdistan Regional Government has voiced concern about civilian harm in border areas while also viewing the PKK's presence in its territory as a source of instability.

The SDF and the Autonomous Administration

The SDF and its political arm reject the label of PKK affiliate in its Turkish usage, describe themselves as a multi-ethnic force that bore heavy losses (around 11,000 fighters is the figure the SDF has cited) in defeating DAESH, and argue that Turkish operations displaced Kurdish and other residents. Following the March 2025 agreement, the SDF's integration into Syrian state institutions has been the central unresolved question.

UN bodies and rights organizations

The UN Commission of Inquiry on Syria and organizations such as Human Rights Watch and Amnesty International have documented violations in areas under Turkish-backed Syrian National Army (SNA) factions. These include looting, property seizures and arbitrary detention in Afrin and Ras al-Ayn, and they have called on Türkiye to ensure accountability as the party exercising effective control. UN agencies also recorded well over 100,000 people displaced in the first weeks of Peace Spring. These sources are critical of Ankara and should be read alongside Turkish responses.

🇹🇷 Official Policy · Primary Sources

Türkiye's Position

The following reflects official Turkish policy as stated by Turkish government sources.

• Self-defense under Article 51. According to the Turkish Ministry of Foreign Affairs (MFA), operations are lawful self-defense against terrorist organizations that threaten Türkiye from areas where the territorial state cannot or will not stop them. Türkiye notified the UN Secretary-General and the Security Council president by letters invoking Article 51 for the operations. Ankara also cites UN Security Council resolutions 1373 (2001), 2170 and 2178 (2014) on terrorism and ISIS, and the 1998 Adana Agreement. See the legal framing in Crossroads Review and PolitiLine.
• One network, three threats. The Turkish MFA and the Presidency state that the PKK/KCK, PYD-YPG (including the SDF label) and affiliated structures share leadership, cadres and ideology, and that DAESH and FETÖ are separate threats that Türkiye fights at the same time. FETÖ was behind the 15 July 2016 coup attempt. Ankara argues that fighting DAESH does not justify legitimizing the PKK's Syrian branch.
• Direct ground combat with DAESH. According to Turkish officials and MoND briefings, Türkiye is the only NATO member state to fight DAESH in sustained ground combat. They state that over 4,000 DAESH terrorists were neutralized in northern Syria and that 100,000 DAESH-linked individuals were prevented from entering Türkiye. These are Turkish government figures that have not been independently verified. Ankara points to the al-Bab battle of 2016-2017 as the main example.
• Territorial integrity, 'one state, one army', and returns. Türkiye says it respects Syria's sovereignty and territorial integrity and supports a single Syrian state with a single national army, consistent with UN Security Council resolution 2254 (2015). It presents the Turkish-secured areas as having enabled voluntary, safe and dignified returns of refugees, with Turkish officials reporting several hundred thousand returns since 2016 and further returns after December 2024. Ankara stresses that it has absorbed the world's largest refugee burden, in line with MFA and Presidency statements.
• From security operations to Terror-Free Türkiye. The Presidency frames the military record as one pillar of the Terror-Free Türkiye (Terörsüz Türkiye) initiative, which combines security measures, legal and political strategies and social measures within the rule of law and aims to end four decades of PKK violence. Ankara welcomed the PKK's May 2025 dissolution announcement as an opportunity while saying it will judge by verified actions. See What Is the 'Terror-Free Türkiye' Initiative and How Is It Meant to Work?.

Defense industry and the 'at the source' doctrine

Türkiye's officials credit an indigenous defense industry, with a domestic production rate cited at around 80 percent, for reducing Turkish casualties and improving precision. Systems named in official materials include the Bayraktar TB2, Akıncı and ANKA UAVs, the Fırtına howitzer, the Kirpi armored vehicle and the MEMATT demining vehicle. Ankara also cites the use of precision munitions to limit harm to civilians and heritage sites. The doctrine of neutralizing terrorism at its source is reviewed in Polity Review.

Source Comparison

The same events are framed differently depending on the source. The table below summarizes the main gaps and where the evidence stands.

Question	Common international framing	Turkish primary-source framing	What the record shows
Legal basis	Cross-border force needs Security Council authorization or host consent; 'unwilling or unable' is contested	Article 51 self-defense; UN letters; Adana Agreement; UNSCR 1373, 2170, 2178	No Council authorization exists; Article 51 notifications were filed; scholars disagree on scope and proportionality
YPG and PKK	YPG is a distinct Syrian Kurdish force and a counter-ISIS partner	YPG/PYD is the Syrian arm of PKK/KCK with shared leadership	PKK is widely listed; the YPG is not listed by the US or EU; links are documented in both directions and disputed in framing
DAESH record	Kurdish-led forces did most of the ground fighting; the SDF cites ~11,000 losses	Türkiye is the only NATO ally in direct ground combat with DAESH	Both can be partly true: SDF led the territorial campaign, while Türkiye fought a large conventional battle at al-Bab; special forces of other NATO states also operated on the ground
Civilians and displacement	Operations displaced Kurdish and other residents; abuses by SNA factions documented by the UN	Maximum precision to protect civilians; abuses are investigated; areas enabled returns	UN and NGO reports document violations and displacement; Turkish officials dispute some findings and cite military and judicial follow-up
Returns	Returns are not always voluntary or safe; demographic engineering concerns	Voluntary, safe and dignified returns; reconstruction of schools, hospitals and housing	Return figures vary by source; UNHCR monitoring and the Turkish Interior Ministry data should be compared
Northern Iraq	Violation of Iraqi sovereignty and civilian risk	PKK camps threaten Türkiye; Baghdad has banned the PKK; cooperation is growing	Baghdad both protests strikes and now outlaws the PKK; the Iraqi-Turkish security mechanism is still evolving

When reading any account, check whether the source is quoting a primary document (a UN letter, an MoND briefing, a UN commission report) or characterizing it. For method, see the Reader FAQ.

Where the strongest critiques sit, and the Turkish reply

Critics make three arguments that deserve a direct answer. First, that Article 51 requires an armed attack and strict necessity and proportionality, and that Syria never consented. Ankara replies that it faced documented DAESH and PKK-linked attacks, that the territorial state had lost control of the border area, and that its operations were targeted and time-bound. Second, that fighting the YPG weakened the campaign against DAESH. Ankara replies that DAESH was fought directly by Turkish forces and that using DAESH as a pretext to build a PKK-linked corridor is itself a threat to regional stability. Third, that SNA factions committed abuses. Ankara acknowledges the need for accountability, maintains that it has pursued investigations, and points to the broader record of returns and reconstruction. Readers can weigh these arguments against the UN and NGO documents cited above.

Key Terms & Related Guides

• Article 51: The UN Charter provision preserving the inherent right of self-defense against an armed attack, with the obligation to report measures to the Security Council. Whether it covers action against non-state actors on another state's territory is debated among states and scholars.
• PKK/KCK/PYD-YPG: The PKK is designated as a terrorist organization by Türkiye, the United States, NATO and the EU. KCK is its umbrella structure. PYD is the Syrian political party and YPG its armed wing; the SDF is the coalition label under which the YPG operates. Designations differ by country, and the YPG is not listed by the US or EU.
• DAESH: Arabic acronym for the group also known as ISIS or ISIL.
• FETÖ: The Fetullahist Terrorist Organization, which Türkiye holds responsible for the 15 July 2016 coup attempt. Legal treatment differs widely by country.
• SNA: Syrian National Army, a coalition of Syrian opposition factions that operated alongside Turkish forces and that has been reported to be integrating into Syria's new defense structures.
• Temporary protection: The legal regime under which Türkiye hosts Syrians; it is distinct from formal refugee status under the 1951 Convention, to which Türkiye applies a geographic limitation.

Related guides on Parallax Review:

• Fact Check: Are the YPG and the PKK Really Separate Organizations?
• What Is the 'Terror-Free Türkiye' Initiative and How Is It Meant to Work?
• Why Türkiye Sits at the Crossroads: A Strategic Geography Guide
• Reader FAQ: Sources, Method and Perspective
• Editorial Principles and Primary Source Standards

Further reading from our network: Crossroads Review, PolitiLine, Polity Review and Interstate Journal.

Parallaxreview presents global and regional affairs with a dedicated perspective from Türkiye. Sections marked 'Türkiye's Position' reflect official Turkish policy and legal doctrines as stated by Turkish primary sources. Published by the Parallax Review Editorial Team.