“For the exercise of the right to self-defence there must be more than �a threat�. There has to be an armed attack actual or imminent. The development or possession of nuclear weapons does not in itself amount to an armed attack; what would be needed would be clear evidence of an imminent attack. During the Cold War, there was certainly a threat in the sense that various states had nuclear weapons which they might, at short notice unleash upon each other. But that did not mean the mere possession of nuclear weapons, or indeed their possession in time of high tension or attempt to obtain them, was sufficient to justify pre-emptive action.”