The nuclear non-proliferation regime, so vital to maintaining international peace and security, is under increasing threat, particularly from countries that deliberately violate their non-proliferation obligations. Experience with North Korea and Iran has demonstrated that non-compliance must be addressed promptly and effectively. Iran has sought to exploit inconsistencies in how the International Atomic Energy Agency (IAEA) reports violations, including its own case and that of Libya, as well as the less worrying but still significant cases of South Korea and Egypt. Clarifying the technical and statutory basis by which the IAEA exposes non-compliance is one immediate way the non-proliferation regime can be strengthened.