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On the 65th anniversary of the second and last time a nuclear weapon was used in warfare, we would do well to remind ourselves of the criteria traditionally used in evaluating whether or not a given conflict conforms to the principles of just warfare. These principles are generally divided into ad bellum (whether the war itself is just) and in bello (the just conduct of war) categories. They were developed over many centuries by a number of philosophers and theologians, including Augustine, Thomas Aquinas, Francisco Suarez, and Hugo Grotius. They are accepted by the major branches of Christianity, including Roman Catholic, Lutheran, Anglican and Reformed.

A. Ad bellum principles:

1. The cause must be justified.

2. The intention must be right.

3. The war must be waged by a competent authority.

4. The war must have a reasonable probability of success.

5. It must be fought only as a last resort.

B. In bello principles:

1. Non-combatants, neutrals and third parties cannot be harmed.

2. Existing laws and treaties, e.g., the Geneva Conventions, must be honoured.

3. The means must be proportionate to the goals.

4. The enemy must know the terms on which peace can be achieved.

5. The goal must be the return of the aggressor to a rightful place among the nations, not its extermination or subjugation.

It perhaps ought to be emphasized that, in just war theory, the primary agent responsible for determining the justice of a contemplated military action is the duly constituted political authority itself, in much the same way that a judge or jury are responsible to determine the guilt or innocence of a defendant on trial. The role played by individual citizens in either of these is necessarily secondary, in part because of the lack of sufficient information available to those not occupying such authoritative offices. In short, we citizens may come to a preliminary assessment, but of necessity such assessment lacks the certainty we might wish for, as well as an authoritative character.

Nevertheless, today’s anniversary provides an occasion to ask a question that, to my knowledge, American Christians have been reluctant to address directly. Given the recent revival of interest in the just war tradition, along with the renewed focus on natural law theories among both Catholics and protestants, how would proponents assess the two bombings of Hiroshima and Nagasaki, given that the latter targeted defenceless civilian populations and failed to distinguish between combatants and noncombatants? Did they violate the in bello principle of civilian immunity? Could they thus be labelled terrorist acts?

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