This chapter sheds light on the security implications of the foreign policy activities of Turkey, the Gulf states, and Iran in the Western Balkans. The chapter begins by presenting a brief history of relations in the post-Cold War period. The second part examines the current state of relations from different perspectives, including the roles of assertive foreign policy choices, soft power institutions, religious institutions, and prestigious economic projects. This study asserts that Turkey, the Gulf states, and Iran have had different impacts on the security architecture of the Western Balkans. Moreover, the state of their relations with the Western Balkans is closely linked to their relations with NATO, the US, and the EU, which determine whether they guarantee or challenge Western Balkan security.