This book critically examines the effectiveness of the International Atomic Energy Authority (IAEA), the international organization charged with preventing the spread of nuclear weapons. Kane Chen looks at its safeguards system in order to evaluate the risk and possibility of a non-nuclear-weapons state that is party to the Non-Proliferation Treaty (NPT) developing nuclear weapons undetected, concluding that gaps that existed in the old safeguards regime prior to the adoption of the stronger IAEA safeguards have remained. To assess the effectiveness of these IAEA safeguards, the book offers a general model to assess the effectiveness of other international regimes ¿ Compliance, Coverage, Counterfactuals, Cohesiveness, and Change (the 'Five C's'). Based on these criteria, the gaps in the old nuclear safeguards regime are identified using four cases: Iraq (1962-1991), North Korea (1965-1994), Libya (1978-2004) and Iran (1967-2006). Each of these cases highlights the gaps and loopholes in the NPT, and in the old and current IAEA safeguards system. Overall, the author demonstrates that the essence of the safeguards system, coupled with the IAEA¿s verification practices and enforcement capabilities, fail to sufficiently deter and detect non-compliance and secret programs. Detecting Nuclear Weapons will be of great interest to students of nuclear proliferation, international security and global governance.