The goal of a planet free from nuclear weapons is at last being taken seriously by the foreign policy establishments of the leading powers. For the Obama administration, followed by the British government, leading the world to accept nuclear elimination as a realistic political objective is a priority. In a world with new nuclear weapon states like India, Pakistan, North Korea, and in the foreseeable future Iran and others, it is only a matter of time before atomic weapons will be used again, either in an authorised, unauthorised or accidental way. The ultimate fear - unfortunately a realistic one - is nuclear terrorism, that bleakly forbidding combination of ideology and technology. At the same time, missile defense seems to have finally made the move from the drawing table to the concrete silo. The Bush administration unilaterally disbanded the ABM treaty (1972) and installed strategic missile defense interceptors in California and Alaska, know commonly as the 'Star Wars' defence system. Even the Democratic administration of President Obama continues to spend nearly $10 billion per annum on missile defense, including land-, and sea-based systems to be deployed in and around Europe. At a certain point in the not too distant future, nuclear elimination and missile defense will either reinforce or weaken each other. Is missile defense a mandatory precondition for arriving at a nuclear-weapons-free-world, as some claim? Or will missile defense make it more difficult, if not impossible, to reach 'global zero'? This book is the first that systematically compares and analyses both options.