The proliferation of nuclear weapons (nuclear proliferation), which is defined as an increasing number of non-nuclear states and, possibly in the future, non-state organizations, gaining access to nuclear weapons, is in the focus of the international security agenda. It is a top priority issue in the official national security policies of the United States, Russia and many other leading countries in the world. Efforts to check nuclear proliferation involve the intensive work of secret services, the use of force against individual states and even large-scale military operations. The efficiency of these efforts is crucial for the world’s prospects and for global security in the foreseeable future. The buildup of nuclear armaments by the largest states, concomitant with the desire of an increasing number of non-nuclear countries to obtain them, have remained closely interconnected phenomena. This is why any nuclear arms race is often described as nuclear proliferation: there exists ‘...