Dec. 30, 2013 7:12 p.m. ET
On Dec. 29, a female suicide bomber blew herself up in the main train station of Volgograd, a city of one million in southern Russia. The explosion killed 16 and wounded scores more. A day later, a similar attack targeted a trolley bus in the same city, killing at least 10. The bombings were a shot across the Kremlin's bow—and a portent of things to come.
The bombings effectively demolish the government's prevailing narrative that, more than two decades after the Soviet Union's collapse, Russia has successfully weathered its own version of the war on terror. In April 2009, Vladimir Putin publicly declared his government's struggle against radical Islam a mission accomplished.
The years since have put the lie to his triumphalism. Islamic militants in the North Caucasus have staged a savage comeback, carrying out atrocities ranging from a brazen suicide raid on the Chechen parliament in Grozny in October 2010 to the assassination of the spiritual leader of Dagestan's moderate Sufi Muslim community in August 2012. Spearheading this violence has been the Caucasus Emirate, Russia's most organized and ruthless terrorist group, which says it seeks "the liberation of the Caucasus" as a prelude to the creation of a regional caliphate in Central Asia.
Russian investigators at a site of the wreckage of a trolleybus after an attack by a suicide bomber in Volgograd, Russia. European Pressphoto Agency
The situation is poised to get much worse because Islamist activity is no longer isolated to the geographic periphery of the Russian Federation. Extreme fundamentalism is also on the rise in Russia's heartland. In Tatarstan and Bashkortostan, both majority-Muslim republics near the Ural Mountains, moderate Islamic clerics have been targets of assassination attempts. Identification with al Qaeda and other radicals, meanwhile, is on the rise. Motorcades bearing the black banners of jihad are now a regular occurrence on the streets of cities in those regions.
Compounding this trouble is the fact that this sprawling nation is on the cusp of major ethnic and religious transformation. Russia's population is constricting rapidly. A recent study by researchers at Russia's Institute of Socio-Scientific Expertise predicted that under a "worst case scenario" the country's population could shrink by nearly a third—to 100 million from roughly 142 million today—by the middle of the century.