On Friday, Defense Secretary Ash Carter called out Russia for bombing a Syrian rebel group that’s backed by the U.S. Since last year, American and Russian warplanes have shared the skies over Syria while supporting different sides in the civil war. Moscow backs the Assad dictatorship; the U.S. is arming rebels who’ve been trying to overthrow it.

The attack by Russian fighter bombers on American-backed opposition forces appeared to be deliberate and to ignore repeated U.S. warnings. It happened in southern Syria where two Su-34s bombed opposition forces, some of them trained and equipped by the Pentagon as part of the war against ISIS. When the American-run command center which tracks Russian …READ MORE