Turkey's cross-border operations to Syria after 2015 in the context of security management

This study analyzes Türkiye's strategies developed in response to the security threats posed by the Syrian civil war after 2011, within the frameworks of international law, security governance, and counter-terrorism policies. The first part discusses the concepts of security, national security,and border security at a theoretical level, while examining the border security issue between Türkiye and Syria. Subsequently, Türkiye's right of self-defense and the legal basis of cross-border military operations are evaluated under international law. The second part explores the concept and types of terrorism and the theoretical approaches to counter-terrorism. It then investigates Türkiye's historical and current struggle against actors such as ISIS/DAEŞ, PKK/PYD/YPG, HTS, and the Free Syrian Army. The third part evaluates Türkiye's military interventions after 2015 Operation Shah Euphrates, Euphrates Shield, Olive Branch, Peace Spring, and Spring Shield—in terms of their strategic, operational, and diplomatic dimensions. The conclusion highlights the transformation of Türkiye's security approach into a multidimensional paradigm that integrates military, diplomatic, and socio-political elements. Furthermore, discussions on a potential new peace process, the state building tendencies of the PKK/PYD/YPG, and the political repositioning of HTS leader al-Jolani are examined within the broader context of regional security strategy.