Noah R. Feldman, Ugly Americans, in The Torture Debate in America (Karen Greenberg ed., 2006).
Abstract: The Canaanite King Adoni-Bezek has just a single line of dialogue in the Bible, but it is one not easily forgotten. Defeated by the combined forces of the tribes of Judah and Simeon, he is subjected to the ordeal of having his index fingers and great toes cut off. Adoni-bezek's philosophical response is that in his day he himself lopped off the fingers and toes of seventy kings: “As I have done, so God hath requited me.” With these last words, the captive king is brought to Jerusalem, where he dies. Today prisoners of war are protected by the Geneva Conventions – but the principle of reciprocity articulated in the king's reflection on the customs of victors still pervades the laws of war. The assumption that all sides might torture or kill prisoners has given way, at least in theory, to the principle that all sides are reciprocally obligated to treat prisoners of war and civilians under occupation humanely. It is fair to say that this norm of international law grew as much from the mutual interests of belligerents in having their own prisoners of war treated humanely as from any deeply held commitment to the dignity of the person. Otherwise it would be almost impossible to explain the anomaly that, according to the rules of war, the enemy may be killed even while he is fleeing, but if captured must be sheltered, fed, and returned to his home when the war is over.