On Strengthening and Expanding the US Nuclear Umbrella to Dissuade Nuclear Proliferation

Many experts and officials are concerned that a failure to stop North Korea from expanding and improving its nuclear weapons stocks and the continued apparent pursuit of nuclear weapons by Iran will spur substantial additional nuclear proliferation. Much of that additional proliferation could be by concerned US allies and friends in Asia and the Middle East, and possibly even by NATO allies such as Turkey. This raises the question of whether strengthening the US nuclear umbrella protecting some allies and perhaps expanding the umbrella to cover other US allies and even new allies could substitute for the independent nuclear forces they might otherwise create. This study explores this topic first in general analytical terms, looks at two specific allies to see how the extended nuclear deterrence guarantees they get from the US might be strengthened. It more important conclusions are 1 that some potential recipients of US nuclear protection can be expected to have significant reasons to prefer their own nuclear deterrent forces to nuclear protection by the US, and 2 that promises to allies to provide extended nuclear deterrence should the need arise may have significant value in dissuading potential regional adversaries from building nuclear deterrent forces of their own.