The ascendance of Sunni Islamist rebels in Syria should be viewed with great caution by Western powers, but the Assad regime’s collapse disables a critical node in Iran’s regional proxy network, a counterterrorism expert explains.

Syrian rebel forces led by Hayat Tahrir al-Sham, or HTS, declared they had ousted President Bashar al-Assad and he had fled Damascus on Sunday. But what is HTS, and how did it rock the long-simmering tensions in Syria? HTS is a Sunni Islamist militant and political group that traces its roots to the beginning of the Syrian civil war.

Secretary of State Antony Blinken’s comment on “direct contact” with the HTS rebels came despite the United States having designated the group as terrorists in 2018