[en] With all the changes in international relations since the end of the Cold War, nuclear weapons have continued to have a position of prominence as the currency of ultimate power. And although a number of countries such as South Africa have given up their nuclear weapons or nuclear weapons ambitions, the nuclear umbrellas of NATO and other alliances continue to expand. More importantly, the objectives embodied in the Treaty on the Non-Proliferation of Nuclear Weapons (NPT), developed in the early 1970s to control the spread of nuclear weapons and to move us towards nuclear disarmament, are under growing stress. Several thousands of nuclear weapons continue to exist in the five nuclear weapon States party to the NPT (China, France, Russia, the United Kingdom, and the United States). And of the three countries that remain outside the NPT, two India and Pakistan have in the last few years demonstrated their nuclear weapons capability, while the third Israel is generally presumed to have such weapons. Most recently North Korea, a party to the NPT, has decided to walk away from the Treaty and, not unlike some other parties to the Treaty, is suspected of working to acquire nuclear weapons. Other States, on the other hand, have opted for the 'poor man's alternative' by pursuing the acquisition of chemical and biological weapons. And in the aftermath of the events of 11 September 2001, the threat of Weapons of mass destruction (WMD) proliferation gained a new dimension: the prospect of sub-national groups seeking to acquire and use these weapons. Faced with this reality, one must conclude that it is futile to try to combat the spread of WMD through a collective, rule-based system of international security and that people have to acquiesce to living in a world plagued with the constant threat of a nuclear holocaust or other disasters? But reliance on a system of collective security to curb the proliferation of WMD will require bold thinking, a willingness to work together, and sustained effort. The following steps, among others, are required: We must modernize the collective security system of the United Nations Charter; We must create an environment in which the use of force, as foreseen in the UN Charter, is limited to situations of self-defence or enforcement measures authorized by the Security Council; We must take concrete steps to delegitimize the acquisition or use of WMD; We must develop a comprehensive regime to ensure that WMD and their components will not fall into the hands of terrorists; We must address decisively chronic disputes that create the greatest incentives for acquiring WMD; Finally, we must work collectively to address global sources of insecurity and instability, including: the widening divide between rich and poor, in which two-fifths of the world's population lives on less than two dollars per day; the chronic lack in many parts of the world of good governance and respect for human rights with despots taking refuge under the cloak of 'sovereignty'; and the increasingly perceived schisms between cultures and civilizations. This is a tall order. But if our aim is to spare the next generation the scourge of a new century of war in which humanity could self-destruct, we have no other alternative