The two terrorist attacks in Volgograd, Russia—on consecutive days—are a true tragedy. The twin bombings have killed dozens and have wounded many more. Both American values and American interests compel the United States to condemn the attacks and express support for Russia’s people and government in dealing with extremist terrorism. While the appropriate immediate U.S. response is clear, however, Russia’s response to terrorism has been uncertain and a mixed success. The recent attacks in Volgograd followed another bombing in the city in October and occurred in the context of regular domestic terrorism throughout Russia, including in its capital Moscow. This...