International security

Russia is endangering world order, says Pentagon chief Ash Carter

Carter said Russia is undertaking "challenging activities" at sea, in the air, in space and in cyberspace. "Most disturbing, Moscow's nuclear saber-rattling raises questions about Russian leaders' commitment to strategic stability, their respect for norms against the use of nuclear weapons, and whether they respect the profound caution nuclear-age leaders showed with regard to the brandishing of nuclear weapons," he said. 

His remarks were perhaps the strongest he has expressed about America's former Cold War foe.