. . . is here proposed with respect to the present discussion concerning the conformity (or lack thereof) between the American bombing of Hiroshima and Nagasaki and just-war rules by way of the principle of double effect:
Blefuscu is at war with Lilliput. The Lilliputians are an island people who require imported shipments of Fertilizer X to grow food and feed themselves. They have arranged to acquire their entire year's supply of Fertilizer X by means of one shipment but, perhaps foolishly, also load the ship with dissassembled fighter planes. No other shipments of Fertilizer X can be arranged in this year.
Losing the fighter planes would be a significant reversal, but not a war-ending event, for the Lilliputians, who have other aircraft. The destruction of the Fertilizer X, however, would result in millions of civilian deaths by starvation. The fighters' presence arguably makes the ship a military target whose destruction would also have consequences for the civilian population of Lilliput. On the other hand, it's clear that the war-winning effect of an attack would come from the starvation of Lilliputians, who would have no choice but to surrender or die.
The Blefuscutian admiralty knows all this. May it order Blefuscu's submarine fleet to track the Lilliputian ship and sink it without violating Catholic moral principles?