BEIRUT -- With U.S. goals expanding and Islamic State nearing defeat, the tangled seven-year war in Syria is growing more complicated as Iran gains the upper hand, Turkey launches a military offensive and Israel is increasingly alarmed by threats to its security.
The risk of a dangerous escalation was clear Tuesday with reports that U.S. airstrikes last week had killed several Russian paramilitary contractors during an attack by pro-government forces on a U.S.-backed militia base in eastern Syria that housed a small number of U.S. troops.
That comes after a week in which Turkey, Russia, Iran and Israel all lost aircraft to hostile fire in the country's increasingly crowded skies.
What began as a civil war in 2011, with U.S.-backed rebels opposed to President Bashar Assad, is now a free-for-all of outside states trying to divide the spoils and expand influence in the Middle East. Assad remains in power and Washington and its allies appear most at risk of losing out, according to diplomats, aid workers and other analysts.
The U.S. role in Syria has expanded under the Trump administration. Until recently, U.S. policy focused primarily on defeating Islamic State, delivering humanitarian aid to civilian communities after critical battles, supporting diplomatic efforts to end the conflict. The U.S. otherwise sought to avoid a broader entanglement in another Middle East war.
Last month, however, the State Department announced that the Pentagon would keep 2,000 U.S. special operations forces, as well as diplomatic teams and others, in the country indefinitely to mop up the remaining militants and to ensure "Iranian influence in Syria is diminished, and Syria's neighbors are secure," a much murkier goal.
"Our military and civilian personnel on the ground in Syria will be targeted, eventually," Robert S. Ford, who left Syria in 2011 as the last U.S. ambassador to serve in Damascus, warned Congress last week. "The Syrian and Iranian governments, and Russia, all want us out of Syria."
Secretary of State Rex Tillerson, on a six-day mission through the Middle East, emphasized the effort to finish off Islamic State, which has been pushed into a sliver of territory in eastern Syria.
The group "remains a very determined enemy and is not yet defeated," Tillerson said Tuesday in Kuwait City at a conference dedicated to raising money for reconstruction in Iraq.
Baghdad estimates it needs $88 billion to rebuild from the widespread destruction left by Islamic State's occupation of cities and towns, and the bitter battle to eject them, which ended in December.