T HE Non-Proliferation Treaty (NPT) provides that five years after its coming into force a conference shall be held to review its operations. This conference will be held in Geneva in May 1975 in circumstances of growing scepticism not only about the Treaty but also about the wider endeavour to control the spread of nuclear weapons, of which it is part. The most dramatic blow struck at the NPT was the Indian nuclear explosion of May 18, 1974. First, the Indian explosion demonstrates the 'failure' of the Treaty, if we take its central objective to have been to restrict the circle of states that had conducted nuclear explosions at the point it had reached in 1970. Secondly, the Indian explosion provides new incentives for other states to acquire nuclear weapons: Pakistan, for example, perceives the Indian explosion as a threat to its security, Japan views it as diminishing its relative status, and everywhere it is taken to confirm the idea that the spread of nuclear explosive technology -is inevitable. Thirdly, India's action has indicated a new route to nuclear proliferation-that of conducting an explosion,and issuinga declaration that it is for peaceful purposes only, while resisting requests for international inspection to authenticate the declaration. Whether or not one takes seriously Indian assurances that no Indian nuclear weapons programme is being planned, this route has been opened up for other states. Fourthly, the Indian action confronts arms control planners with the problem of how to deal with peaceful nuclear explosions (PNEs) conducted by non-nuclear weapon states-a problem that the NPT sought to avoid by laying down, in effect, that nuclear explosions can be -peaceful only if they are conducted by nuclear weapon states. Fifthly, by identifying the NPT as part of the system of super-power domination, and successfully defying it in the name of the rights of the underprivileged, India has helped to diminish the legitimacy of the Treaty and to make more respectable further acts of defiance by itself and others. However, the most important factors working against the NPT woul d be having their effect even if the Indian nuclear explosion had not taken place. The capacity to make nuclear weapons, which the NPT does little to restrict, is spreading at an accelerating rate as a consequence of the rapid rise in the number of plutonium power