US Sen. Jim Risch (R-ID) speaks during a Senate Foreign Relations Committee hearing at the US Capitol, in Washington, DC, May 21, 2024. Photo: Graeme Sloan/Sipa USA via Reuters Connect

US lawmakers have celebrated the collapse of Bashar al-Assad’s regime in Syria but also cautioned that many of the rebel Islamist groups who helped to oust the longtime president could pose further threats to the United States and its allies in the Middle East.

Assad fled the capital of Damascus on Sunday as a coalition of rebel groups stormed the capital, ending his family’s five-decade rule. The deposed leader, who has been accused of war crimes for his crackdown on rebel forces since 2011, was a partner of Russia and allied with Iran, which for years has used Syrian territory to send weapons to its terrorist proxy Hezbollah in Lebanon.

However, many Western observers have expressed concern that the leading Syrian rebel faction, Hayat Tahrir al-Sham (HTS), is a group formerly allied with Al Qaeda and which is designated a terrorist organization by the US, European Union, Turkey, and the UN.

Following Assad’s fall, US lawmakers were quick to call for both optimism and vigilance.

Sen. Chris Van Hollen (D-MD), a member of the Senate Foreign Relations Committee, posted on X/Twitter that he hopes for a “better future for the Syrian people” following the fall of Assad, but warned about the potential threat of the terrorist group Islamic State (ISIS) in the region. 

“As we bid good riddance to Assad, and hope for a better future for the Syrian people, we must remain vigilant regarding the threat of ISIS and continue to support our partners the Syrian Kurds. This is not a time to let our guard down,” Van Hollen said.

On Sunday, US Central Command (CENTCOM) announced the successful bombing of ISIS camps and fighters in central Syria, saying that the operation was carried out to “disrupt, degrade, and defeat” the terrorist group and prevent it from capitalizing on the fall of the Assad regime. 

Sen. Jim Risch (R-ID), the ranking member of the Senate Foreign Relations Committee, expressed optimism at the new “opportunity” that Assad’s departure represents. However, he added that Syria must adopt a democratic process to select its next leader.

“While it is a time for opportunity, it is also a potentially dangerous time for the region,” Risch said in a statement. “Moving forward, it is imperative the Syrian people choose their next government and Assad faces long-overdue justice for his war crimes.”

Sen. Ben Cardin (D-MD), chair of the Foreign Relations Committee, called for a “peaceful transition” of power in Syria and warned the country’s new leaders to “avoid the chaos that often follows the fall of a tyrant.”

Sen. Tom Cotton (R-AK) stated that the US must remain “vigilant” in protecting its allies and citizens across the region. 

“While it’s welcome news to see the humiliation of Russia and Iran and the end of Assad’s tyranny in Syria, we must be vigilant about protecting our citizens, interests, and allies in the region,” hewrote on X/Twitter. “Distrust but verify the intentions of anyone that might come to power.”

A US State Department spokesperson said on Monday that the Biden administration was seeking ways to engage with Syrian rebel groups and was reaching out to partners in the region such as Turkey to help launch informal diplomacy.