The threat of atomic destruction has heightened the criminal irresponsibility of aggression, the employment of war as an instrument of national or bloc policy. Correspondingly, the moral obligation to discourage such a crime or, if it occurs, to deny it victory, has been underscored. The consequences of a successful defense are fearful to contemplate, but the consequences of a successful aggression, with tyrannical monopoly of the weapons of mass destruction, are calculated to be worse. While the avoidance of excessive and indiscriminate violence, and of such destruction as would undermine the basis for future peace, remain moral imperatives in a just war, it does not seem possible to draw a line in advance, beyond which it would be better to yield than to resist. Reinhold Neibuhr.… the person who deeply desires peace rejects any kind of pacifism which is cowardice or the simple preservation of tranquility. In fact, those who are tempted to impose their domination will always encounter the resistance of intelligent and courageous men and women, prepared to defend freedom in order to promote justice. Pope John Paul IIFor two generations the United States has maintained with its principal adversary, the Soviet Union, a security relationship based upon the deterrence of war by the possession of means deemed adequate to inflict unacceptable levels of damage in response to a Soviet attack upon the United States or its allies. Against the Soviet Union, the world's largest land power, in possession of superior conventional forces that could be launched against Western Europe and other peripheral regions of the continents of Europe and Asia, the United States has held nuclear capabilities as the ultimate weapon to be invoked in support of those interests deemed to be most vital to American security.
