Did the US withdrawal from Afghanistan help ISIS regroup?

A permissive environment enabled ISIS-K to plan attacks beyond its borders

Credit: Russian Emergency Ministry

Last week's terrorist attack on a concert hall in Moscow, one of the deadliest in Russia in decades, has once again focused attention on the Islamic State Khorasan Province (ISIS-K), ISIS's branch in Central Asia, which immediately claimed responsibility. The ISIS affiliate group operates primarily in the Afghanistan-P…