The expiry of the Strategic Arms Reduction Treaty-1 (START-1) in 2009 and an urgent need to conclude a new US-Russian agreement on strategic nuclear weapons so that the oldest and biggest nuclear powers demonstrate some progress in implementing Article 6 of the Non-Proliferation Treaty (NPT) in proximity of the 2010 NPT Review Conference has drawn international attention to the interface between the progress/crisis in nuclear disarmament and strengthening/weakening of the NPT regime. This article analyses major past and potential future steps in Russian-US nuclear arms reductions, in dealing with excessive fissile materials, in preventing weapons of mass destruction (WMD) terrorism, and in their interconnection with the non-proliferation tasks.