A recent incident in Syria shows how easily U.S. involvement in the conflict could escalate:

The Pentagon warned the Syrian government Friday not to strike U.S. and coalition personnel in Syria, a day after the regime carried out airstrikes in an area near American special operations forces, prompting the U.S. to scramble jets to protect them. The U.S. jets arrived just as the two Syrian government Su-24 bombers were departing, according to Pentagon spokesman Capt. Jeff Davis, who said none of the U.S. forces on the ground were harmed. The Syrian government bombers had been striking Kurdish positions near the city of Hasakah, where the U.S. has been backing Kurdish forces in the fight against Islamic State.

Fortunately, this episode didn’t lead to a clash with the Syrian government, but a future one very well might. When the U.S. backs proxies in a foreign civil war and puts U.S. forces on the ground with them, it opens the door to new and unexpected conflict with other armed groups in the country. By extending protection to U.S. proxies in Syria, the U.S. could find itself drawn into yet another conflict in Syria. Anti-regime groups would have a strong incentive to put the U.S. in that position. The more U.S. forces that are sent into the country, the greater the chances of an incident that could lead to a wider war, and Clinton is on record in favor of sending more special forces into Syria. This episode underscores the absurdity of the administration’s many statements that U.S. forces aren’t in combat in Syria, and it reminds us how quickly a supposedly “limited” intervention could spiral into something much worse.