This essay analyses the role of public opinion in the formation of US and Turkish policy toward the conflict in Syria. The United States and Turkey were chosen because they are key players in the Syrian conflict. In both countries, public opinion played a role in the formation of foreign policy. As North Atlantic Treaty Organization allies, they could be expected to act along similar lines. Moreover, despite seemingly different contexts, public opinion in both the United States and Turkey was reluctant to support a more intense involvement in the Syrian conflict. However, there was a visible shift in public opinion after the involvement in Syria started to be framed as a fight against terrorism, mostly referring to the so-called Islamic State and, in Turkey’s case, Kurdish groups.