|Fr. Edmund A Walsh, S.J. and Gen Douglas MacArthur|
"greater need for clear heads, steady hands and great hearts at the controls of human destiny, for men who walk humbly in the sight of God but keep their powder dry"
Walsh's most stridently militarist position was his justification of a peremptory nuclear first strike by the United States against the Soviet Union. Writing immediately after the outbreak of war on the Korean peninsula which he interpreted as the "final confrontation" between "two great centers of world power whose basic and irreconcilable character" was known to Soviets decades ago, Walsh argued that all states were obligated to protect their populations from attack. Preemptive attacks were morally just. The United States, for example, would have been justified in intercepting and destroying the Japanese aircraft attacking Pearl Harbor. With a "Soviet feint in some remote area of Asia or the Middle East," the U.S. defense system had better keep its eyes fixed on the Northwest and Arctic sector for a sneak surprise attack.
If the U.S. government had "sound reason to believe (that is, had moral certitude)" that a surprise attack was being planned then President Truman was justified in "taking measures proportionate to the danger" including use of atomic bombs.
While the results would be tragic and horrific, there was no immorality in the United States government choosing the lesser of two evils. Walsh justified military force in the abstract by pointing out that "even Christ himself did not disdain to seize the lash and drive the hypocrites out of the Temple". Writing on this same issue of the atom bomb and the Christian conscience in Total Empire he ends the book with the rather ominous sentence: "The debate is not whether we can afford to do the necessary things for the defense of Christian civilization -- but can we afford not to do them?"
Link (here) to read the full paper with citations.