In Syria, Potential Ally’s Islamist Ties Challenge U.S.

ANTAKYA, Turkey — A rebel group with thousands of fighters, political clout and close ties to key regional powers has emerged as one of the most powerful opposition forces in Syria in recent months. It has vowed to fight the Islamic State and called for engagement with the West.

But despite a long struggle by the United States to find a viable opposition in Syria to counter President Bashar al-Assad and fight the Islamic State, the Obama administration has shown no interest in working with the group, Ahrar al-Sham, or the Free Men of Syria.

The problem for the United States is Ahrar al-Sham’s grounding in militant Islam — a concern that has also dogged previous efforts to find partners in Syria