The nuclear arms control regime-centered on the 1968 Nuclear Nonproliferation Treaty (NPT)-faces five challenges: failure of nuclear disarmament by the five NPT-licit nuclear powers (China, France, Russia, the United Kingdom and the United States); possible cheating by non-nuclear signatories like North Korea and Iran; India, Israel, and Pakistan remaining outside the NPT; terrorists' interest in acquiring and using nuclear weapons; and the safety, security and proliferation risks of the increased interest in nuclear energy to offset the financial and environmental costs of fossil fuel.