Among the most cited risks are: nuclear proliferation contributes to the risk of unstable governments or leaders gaining access to nuclear weapons and using them in an irresponsible way; in countries newly acquiring nuclear weapons, safeguard systems preventing nuclear accidents and incidents may be insufficient or altogether non-existent; in regions dominated by a high degree of tension, a nuclear power may be tempted to launch a pre-emptive nuclear strike before its opponent has also gained access to nuclear weapons. The initial phase of regional nuclear arms races are is prone to strategic instability. A local nuclear war may involve major nuclear powers through multilateral defence treaties or perceived threats. An unidentified nuclear strike against a nuclear power may be misinterpreted and lead to a punitive strike against the wrong opponent. Smaller nuclear powers may be manipulated into making nuclear attacks. Private corporations and groups outside governmental control, including terrorists and criminals, may acquire access to nuclear weapons.