The U.S. Army was recently given a specific military order. According to the top U.S. commander in Iraq, Lieutenant-General Ricardo Sanchez, the mission is to kill the radical Shia cleric, Moqtada al-Sadr.

This order to target al-Sadr for extra-judicial killing is perfectly legitimate and lawful under the laws of war. Al-Sadr is a combatant, and it is proper to kill a combatant during a war unless he surrenders first. It does not matter whether the combatant is a cook or bombmaker, a private or a general. Nor does it matter whether he wears an army uniform, a three-piece suit or a kaffiyeh. So long as he is in the chain of command, he is an appropriate target regardless of whether he is actually engaged in combat at the time that he is killed or is fast asleep. Of course, his killing would be extra-judicial. Military attacks against combatants are not preceded by jury trials or judicial warrants.

Al-Sadr fits squarely into any reasonable definition of combatant. He leads a militia that has declared war on American and coalition forces, as well as on civilians, both foreign and Iraqi. He is at the top of the chain of command, and it is he who presses the on-off button for the killings. Like Osama bin Laden and Mullah Muhammad Omar, he is a proper military target, so long as he can be killed without disproportional injury to non-combatants. If American forces can capture him, they are permitted that option as well, but they are not required — under the laws of war — to endanger the lives of their soldiers in order to spare al Sadr's life. Indeed, unless he were to surrender, it is entirely lawful for American troops to kill him rather than to capture him — if it were decided that this was tactically advantageous. Although U.S. commanders mentioned capture along with killing as an option, it may well be preferable not to capture al-Sadr, for fear that his imprisonment would provoke even more hostage taking.

The world seems to understand and accept the American decision to target al-Sadr for killing, as it accepts our belated decision to try to kill bin Laden and Mullah Omar. There has been little international condemnation of America's policy of extra-judicial killing of terrorist leaders. Indeed the predominant criticism has been that we did not get bin Laden and Mullah Omar before September 11.

How then to explain the world's very different reaction to Israel's decision to target terrorist leaders, such as Sheikh Ahmed Yassin and Abdel-Aziz al Rantisi, the former leaders of Hamas? Surely there is no legal or moral difference between Yassin and al-Rantisi, on the one hand, and al-Sadr on the other. Yassin and al-Rantisi both ordered terrorist attacks against Israeli civilians, and praised them when they succeeded. Each was responsible for hundreds of civilian deaths and was involved in ordering and planning more terrorist attacks at the time of his death. They were terrorist commanders, just as al-Sadr is. They were both killed, along with their military bodyguards, in a manner that minimized civilian casualties, even though they generally — and unlawfully — hid among civilians, using them as human shields. Israel waited until they and their guards were alone and then targeted them successfully. There was no realistic possibility of capturing them alive since they had sworn to die fighting, and any attempt to extirpate them from the civilians among whom they were hiding would have resulted in numerous civilian casualties.

Reasonable people can disagree about whether the decision to target Yassin, al-Rantisi, al-Sadr, bin Laden or any other terrorist is tactically wise or unwise, or whether it will reduce or increase the dangers to civilians. But no reasonable argument can be made that the decision to target these combatants — these terrorist commanders — is unlawful under the laws of war or under international law...