Reuters: “U.S. and Russian military officials signed a memorandum of understanding on Tuesday that includes steps their pilots should take to avoid an inadvertent clash over Syria as they carry out separate air strikes against militant groups, the Pentagon said.”

“The issue of aircraft safety started after Russia started bombing targets in Syria last month. Moscow says it is attacking Islamic State, but many of its air strikes have hit territory held by other rebel groups fighting against Russia’s Syrian ally, President Bashar al-Assad.”