In recent decades, verification methods, technologies and procedures have been significantly developed further, both technically and procedurally. The competence and expertise of the IAEA and the CTBTO have been considerably improved and national as well as international verification research programmes have been developed. A global verification culture with a lot of knowledge, expertise and experiences has been evolved in some areas. When it comes to the concrete reductions and the credible destruction of nuclear warheads, verification efforts today focus on delivery systems and the number of deployed warheads. Under New START, the USA and Russia are verifying their bilateral obligations until 2026 based on bilateral inspections. Transparency of the current global NWSs arsenal with regard to the exact number of warheads, their operational status, storage and production sites including the fissile material is not existing yet. More R&D is necessary to develop new verification tools. Yet, the international community is not part of the concrete dismantlement of nuclear warheads that are no longer needed or the fissile material released in the process. “Transparency and irreversibility” as well as “safety and security” and non-proliferation standards are key disarmament criteria which have to be applied to future reduction cycles. A dismantling or destruction of a nuclear warhead under the control of foreign inspectors has not yet taken place due to the proliferation concerns under der Non-Proliferation Treaty Art. II and III, which prohibit the disclosure of sensitive information, which would take place if inspectors from NNWS were involved in the dismantlement process and if they have direct insight into the design and composition of the warhead. It is therefore clear that reliable verification of the dismantlement and destruction of a warhead must be a central element of future multilateral nuclear disarmament. The NPT and the TPNW verification demands imply different scenarios, methods and requirements for such options. It is important to understand the existing verification measures and capabilities, so that reduction and elimination proposals cannot be rejected due to their alleged ineffectiveness. Additionally, it is also clear that the vision of ultimately eliminating nuclear weapons worldwide will not be achieved in one big step but in a step-by-step approach and needs specific verification arrangements for multiple scenarios.