David Satter is a senior fellow of the Hudson Institute and a fellow of the Foreign Policy Institute of the Johns Hopkins University School of Advanced International Studies (SAIS). His latest book, Haunted Ground: Russia and the Communist Past, is due out next year from the Yale University Press.

IRON FIST

Vladimir Putin isn’t sending troops into Ukraine merely to protect Russian interests abroad. He’s also trying to protect his regime at home.

After two female suicide bombers struck the Moscow subway, the hunt is now on for a 21-strong "Black Widow" terror cell. David Satter on why Russia is bracing for more attacks.