Syria has long been described as one of the world's most active state sponsors of terrorism and, indeed, support for radical groups has long been an integral part of Syrian foreign policy. However, this support is nuanced and complex, reflecting Damascus's desire to both exploit terrorist groups and limit them. Damascus has bolstered the Palestinian cause and constrained it, encouraged radicals in Lebanon and crushed them, and otherwise demonstrated considerable care and variance in how it uses terrorist groups. In many ways, Syria represents an “antagonistic” sponsor of terrorism, helping many particular groups become stronger but also working to control them and subordinate their overall cause to Syrian domestic and geopolitical goals.

Such a cloudy picture is striking, as the list of Syrian links to terrorist organizations is long. Over the years, Damascus has assisted a range of secular left-wing Palestinian groups, such as Fatah, the Democratic Front for the Liberation of Palestine, the Abu Musa group, al-Saiqa, the Abu Nidal Organization (ANO), Popular Front for the Liberation of Palestine (PFLP), the Popular Front for the Liberation of Palestine– General Command (PFLP-GC), and various defectors from Fatah. Syria also has provided sanctuary and other forms of assistance to Palestinian Islamist groups such as the Palestine Islamic Jihad (PIJ) and HAMAS. In addition to supporting Palestinian groups active against Israel, Damascus gave sanctuary to the Kurdistan Workers' Party (PKK), which sought a Kurdistan independent from Turkey, until 1998.