On X, Vance was responding to a post from a Washington Post columnist that praised the collapse of Bashar al Assad’s regime, saying that opinions lauding the rebels, who are an offshoot of Al Qaeda, make him “nervous.”

“As President Trump said, this is not our fight and we should stay out of it. Aside from that, opinions like the below make me nervous. The last time this guy was celebrating events in Syria we saw the mass slaughter of Christians and a refugee crisis that destabilized Europe,” Vance said.

He added, “Many of ‘the rebels’ are a literal offshoot of ISIS. One can hope they’ve moderated. Time will tell.”

A 2017 State Department report on religious freedom in Syria found that ISIS and the al Qaeda-linked Hayat Tahrir al-Sham, which led the insurgency, targeted religious minorities in the country, including Christians, with killings, kidnappings, physical mistreatment, and arrests.

The Syrian rebels overtook the capital city of Damascus early Sunday, as Assad left for Moscow, Russia, shortly before. Footage from the city streets showed supporters of the regime change toppling statues, burning buildings, and raiding Assad’s private residence. Thousands of Syrians also fled to the Lebanese border, hoping to escape before the rebel takeover.

Trump has promised not to get involved in Syria; he withdrew American troops from the region during his first term as president.

President Joe Biden praised the end of Assad’s “brutal, authoritarian rule” and called the end of the regime a moment of “historic opportunity.”