Over the course of the last 20 years, Turkish-Syrian relations represent one of the most profound cases of position reversals in the realm of foreign policy. From border and water disputes and Syria’s harboring of Kurdistan Workers’ Party leader Abdullah Öcalan that brought the two countries to the brink of war in the late 1990s, relations not only relaxed but became downright cordial in the 2000s. Following the brutal crackdown of Bashar al-Assad’s regime on protesters during the Arab Spring, however, then-Turkish Prime Minister Recep Tayyip Erdo?an abruptly turned on his former friend to call for his ouster. Erdo?an’s desire to see Assad removed from power extended to the support of Salafi jihadist forces against the Syrian regime as well as a refusal to assist the American forces in the fight against the Islamic State unless the US committed to ensuring that Assad would fall. What best explains these seismic shifts? This paper applies insights from decision-making approaches to parse out the dynamics driving the drastic changes in Turkey’s foreign policy orientation towards Syria throughout the past two decades. While acknowledging the domestic politics incentives present in Turkish decision-making, the paper also explores the less addressed but constitutively relevant roles of social identities and emotions. In articulating its arguments, the paper draws on data collected from fieldwork in Turkey as well as government documents and news and social media sources.