Jerome Frank describes the increasing blurring of rules and therefore of criteria for atrocity, by the changing technology of war. He sees these trends as having malignant psychological impact upon returning veterans as well as upon American society at large.
Jerome D. Frank, M.D.
As long as wars were fought primarily by organized, uniformed soldiers, it was possible to maintain a distinction between legitimate killing and war crimes. A soldier could justifiably try to kill his enemy counterpart who was trying to kill him, but it would be a criminal act wantonly to attack a member of the enemy population whose fate was irrelevant to the outcome of the struggle and who did not threaten the soldier's life.
Under conditions of modern war, however, this distinction has become increasingly blurred. Since a nation's war potential now depends heavily on its industrial capacity, all productive citizens have in a sense become combatants--that is, war has become "total." Hence the use of artillery and air power to inflict massive carnage on civilians has come to be viewed as a necessary part of the struggle for victory. So this form of mass murder has been accepted as legitimate. Furthermore, wars are increasingly characterized by guerilla activities in which it is impossible to distinguish friend from foe. An enemy soldier may be dressed as a peasant; and a child, a crippled old man or a nursing mother may hurl a grenade. So the exhausted, hungry, frightened soldier, thirsting for revenge for the deaths of comrades in arms, is all too prone to attack civilians first and ask questions afterwards.
In short, whatever tidiness old-fashioned wars may have possessed has long since vanished, and with it attempts to arrive at generally agreed upon definitions of war crimes are doomed to futility. Since one cannot distinguish between acceptable and unacceptable forms of killing by the degree of suffering