The U.S. military just shot down another Syrian drone

Another day, another escalation in Syria.

The U.S. military shot down an armed Syrian government–operated drone Tuesday after it was seen “advancing on coalition forces” and displaying “hostile intent,” U.S. Central Command said in a statement.

The drone, downed near a combat outpost in the town of At-Tanf, was the second one shot down by U.S. forces in 12 days; the downing comes as Pentagon officials are working to defuse heightened tensions in southeastern Syria.

U.S.-led coalition forces had already set off a fresh round of controversy Sunday, shooting down a Syrian warplane that reportedly bombed nearby Syrian Democratic Forces, who are allied with the U.S. in their fight against ISIS.

That move elicited a round of threats from Russia’s defense ministry, which indicated it could shoot down the next U.S. jet flying west of the Euphrates River, and raised fresh concerns over the expanded nature of U.S. involvement in Syria’s protracted six year war.

Here are the basics:

• Russia said it was cutting the “deconfliction line,” a key communication channel between Moscow and Washington used to prevent mixed messages and avoid military collisions between the two powers.
• The U.S.-led coalition’s actions were further complicated by Iran, which over the weekend launched strikes on ISIS targets in Eastern Syria — Iran’s first missile strikes into the country.
• “As the Islamic State’s territory in Syria shrinks, the U.S. is increasingly being put in direct contact with Syria and its allies,” said Bill Roggio, editor of the Long War Journal. “The U.S. must decide if it wants to continue to actively support its proxies in the Syria civil war. If it does, it will be in direct conflict with Russia, Iran, Syria, and hostile Shia militias.”
• The U.S. has maintained its broadening military involvement in Syria is part of the global fight against ISIS, and has avoided engaging directly with the regime of Syrian President Bashar Assad and the larger civil war playing out in Syria.

The last time Russia threatened to cut off the deconfliction line was in April, when the U.S. launched missiles at a Syrian airbase in what ultimately amounted to a warning shot in retaliation for Assad’s continued use of chemical weapons.