Why would Putin put himself in a risky spot by working with the Taliban? It’s a case of aligning himself with the enemy of his enemy.

A U.S. commander last month told Congress that ISIS has gained strength in Afghanistan in recent months, with as many as 3,000 fighters there.

Putin has long worried about thousands of jihadists from Russia’s Caucusus region and the former Soviet republics going to fight with ISIS in Syria.

He may be trying to cut off the pipeline of fighters closer to home, in Afghanistan, one expert told CNN.