Catholics, as are others, are confronted with a moral challenge. While it is clear that any terrorist act, whether it results in the death of others or not, or includes the use of nuclear material or not, is intrinsically evil, the question remains about whether the development and use of nuclear weaponry by recognized nations and even in an acknowledged “just war” context is moral.

The Church actually has had much to say regarding nuclear warfare in the past half century since the United States became the first and only country to utilize atomic weaponry during wartime. But the moral issue today has grown significantly more complex for the Christian who honestly struggles with the issue of the moral legitimacy or illegitimacy of nuclear weapons.



While a moral analysis would generally start with the rather straightforward question about whether nuclear weapons are a moral option in a just war, the analysis is stretched by those who would suggest that nuclear weaponry can be justified as a legitimate “deterrent.” What begins as a moral question based on jus in bello — what is morally acceptable during a just war (i.e., “Can we ever have a situation that justifies the use of atomic weapons?”) — now evolves into a question involving political strategy (Can a country morally justify a nuclear arsenal using a “legitimate defense” argument?).

Lastly, there are those who would raise a moral question that is even more fundamental than either the jus in bello or the strategic deterrent justification. They ask whether any use or development of nuclear fission or fusion even for peaceful purposes such as energy production can be morally justified in light of environmental concerns and/or potential for abuse. It is precisely this potential for abuse argument that is often raised as a concern about nuclear power plants in some non-Western countries.

These three issues all deserve a response, especially as countries struggle to protect themselves from the possible use of nuclear material by terrorists, let alone nation-states.

A legitimate tradition of pacifism

We begin by noting the fact that while there is a clear legitimate tradition of Christian pacifism in the Church’s history, there is similarly an embrace of the “just war” tradition that is based on a moral right to self defense, both for individuals and for nations: “…governments cannot be denied the right to legitimate defense, once every means of peaceful settlement has been exhausted” (Gaudium et Spes, 79). The moral questions before us here will not deal with the meaning of “just war” specifically, but rather with the “nuclear issue.”

FIRST: In the context of a legitimate conflict, would a nation be justified in using a nuclear weapon?

In visiting Hiroshima, Pope John Paul II said, “In the past it was possible to destroy a town, a region, or even a country. Now it is the whole planet that has come under threat.” While the Church never condemns nuclear weapons as instrinsice malum (intrinsically evil) in themselves, magisterial teachings make it clear that they are forbidden for use, either tactically or strategically, during even legitimate conflicts. “The mere fact that war has regrettably broken out does not mean that everything becomes licit between the warring parties.” (Catechism, 2312).

Using this principle, the Vatican II Council Fathers, in Gaudium et Spes, teach the church regarding nuclear weapons:

“…acts of war involving these weapons can inflict massive and indiscriminate destruction far exceeding the bounds of legitimate defense.…With these truths in mind, the most holy Synod makes its own the condemnation of total war …and issues the following declaration. Any act of war aimed indiscriminately at the destruction of entire cities or of extensive area along with their population is a crime against God…It merits unequivocal and unhesitating condemnation” (GS, n. 80).

In its recent Compendium, the Pontifical Council for Peace and Justice states:

“The Magisterium condemns ‘the savagery of war and asks that we be considered in a new way. In fact, ‘it is hardly possible to imagine that in an atomic era, war could be used as an instrument of justice’“ (n. 497).

Those Catholics that would hold to a moral justification of the nuclear bombs dropped on Nagasaki and Hiroshima are reminded that Catholic moral theology can never be reduced to a “utilitarian calculus.” In other words, moral actions can never be evaluated according to a utilitarian relativity, where “the end justifies the means.”

We are reminded that the deliberate targeting of civilians cannot be dismissed with a casual reference to either the principle of double effect or that of the “lesser of two evils.” Our Catechism reminds us that “non-combatants must be respected and treated humanely. Actions deliberately contrary to the law of nations ...