Scholars have long recognized domestic politics’ role in determining foreign policy choices (for example, Hobson 1975 [1902]; Tilly 1985; Snyder 1991). The emphasis on domestic politics shifted Turkey scholars' focus from the international order to the national social, economic, and ideological factors of foreign policy. Several studied the role of ideological and pragmatic politics in shaping the AKP’s foreign policy revisionism (Kirisçi 2009; Zarakol 2012; Hintz 2018, Cağaptay 2019a). This chapter takes this analysis one step further to examine Turkey’s changing relations with Arab countries, particularly Turkey’s involvement in Syria as related to developments in domestic politics and the survival tactics of a populist authoritarian leader. The first section lays out the historical and domestic background of Turkey’s recent opening toward Arab countries and will explain how this policy became untenable following the Arab uprisings. The second section offers a closer look at the conditions of the diversion from the “soft-power” and “zero- problems with neighbors” approach that once defined the AKP’s foreign policy opening. It explains Turkey’s military and administrative expansion in Syria and how President Erdoğan and the Turkish military justify this policy primarily by the “myth of security”—the idea that Turkey’s safety can only be maintained through expansion (Synder 1991). How- ever, this policy stems from the parochial interests of nationalist groups, on which the political survival of the President and the AKPs depends. Moreover, as Turkey’s involvement in Syria leads to costs that exceed associated benefits for security, peace, and prosperity in the region, this corresponds to what Synder refers to as “overexpansion.” The final section elaborates on the costs of Turkish policy in terms of deepening ethnic cleavages, radicalization, and fragmentation in Syria.