The destructive power of nuclear weapons complicated application of the just war insistence on limited warfare, especially in terms of discrimination between combatants and civilians, often referred to as noncombatant immunity. For example, some viewed nuclear warfare as intrinsically opposed to the jus in bello criteria. Statements by two of the largest U.S. religious denominations epitomized these concerns. In a 1983 letter, the United States Conference of Catholic Bishops began their discussion of U.S. nuclear policy with a denunciation of any use of nuclear weapons against civilian sites such as cities. They went on to question the very concept that nuclear warfare could be limited or contained in any meaningful sense and called for full nuclear disarmament. Similarly, in 1986 the United Methodist Council of Bishops in the United States wrote In Defense of Creation: The Nuclear Crisis and Just Peace in which they too called for complete nuclear disarmament. The council specifically condemned the policy of nuclear deterrence and claimed that instead of encouraging peace, it led to perpetual hostility and encouraged a nuclear arms race and nuclear proliferation.
Other theorists, such as the Protestant theologian Paul Ramsey, believed that nuclear weapons could be used within a moral framework given the right conditions. Although Ramsey prioritized discrimination between combatants and noncombatants, for example, he thought that counterforce nuclear targeting (as opposed to counterpopulation targeting) was justifiable based on just war principles. He recognized that some noncombatants would inevitably die in a nuclear attack on military targets. Nevertheless, for Ramsey the rule of double effect as developed by just war theorists during the Middle Ages allowed for the possibility of noncombatant casualties. According to the rule, a soldier could proceed with an attack likely to harm noncombatants provided that the injury to civilians was unintentional and that the good effect of the action outweighed the negative consequences. Ramsey applied similar logic to his understanding of nuclear deterrence. Since a discriminate, proportional use of nuclear weapons was morally justifiable, according to Ramsey, the threat of nuclear retaliation was also justifiable. On the other hand, he argued that the indiscriminate use of nuclear weapons on population centers was immoral, and therefore the threat of indiscriminate use of nuclear weapons was also immoral. Based on these criteria, he repudiated the policy of mutual assured destruction (MAD) and urged policymakers to develop a new generation of low-radiation yield, discriminate nuclear weaponry.
Unlike the approach taken by Ramsey and other theological writers, Michael Walzer's Just and Unjust Wars articulated just war principles within the context of an emphasis on human rights. Walzer's theory of supreme emergency in particular left room for immoral acts in extreme circumstances. He suggested that a political community had a right to defend itself and temporarily abrogate the moral limitations on warfare if its very existence was threatened and if all other options had been exhausted. Although not restricted to nuclear warfare, this principle left a narrow opening for counterpopulation nuclear threats and for counterpopulation nuclear warfare.
Just war positions during the Cold War developed around other themes as well. Some condoned the possession of nuclear weapons for deterrence purposes but objected to any actual use of the weapons. Others emphasized a no-first-use policy and insisted that nuclear bombs only be used in retaliation for nuclear attacks. Still others saw nuclear weapons as an acceptable response to conventional attacks under certain circumstances. Another area of debate centered on the morality of seeking nuclear superiority.
The demise of the Soviet Union in 1991 and the end of the Cold War diminished the immediate threat of nuclear attack and signaled a new context for just war theorizing regarding nuclear ethics.
Joseph W. Williams
Miller, Richard Brian. War in the Twentieth Century: Sources in Theological Ethics. Library of Theological Ethics. Louisville, KY: Westminster/John Knox, 1992.; Walzer, Michael. Just and Unjust Wars: A Moral Argument with Historical Illustrations. 3rd ed. New York: Basic Books, 2000.