Means shape ends. The partial defeat and vengeful settlement inflicted on Germany after World War I led to World War II. The next time, defeat was total and the settlement magnanimous, leading to a democratic and now reunited Germany.

President Bush bears this lesson in mind when he draws a distinction between the people of Iraq and its dictatorial regime. His strategic planners must make Bush's rhetorical distinction a real one by minimizing the physical damage that U.S. military action will do to Iraq's already brutalized and downtrodden civilian population. U.S. planning must emphasize the Iraqi people's liberation, not its destruction.

But Bush must rely on three blunt instruments to accomplish the aims of Operation Desert Shield: economic sanctions, air superiority and the Arab units that have joined this American-led endeavor. Critics rightly point to past failures by each used separately. A combination of the three can succeed against Saddam Hussein, however.

Bush has up to now usefully portrayed sanctions as the primary alternative to war. This gives America's allies and other nations a powerful incentive to make the sanctions effective and thereby postpone military action. Sanctions have helped purchase solidarity.

But they are prelude, not alternative, to war if Saddam continues to refuse to withdraw from Kuwait. Sanctions soften up Saddam's war machine. They also demonstrate to Iraq's population how united the world is in opposing the Kuwait invasion. The utility of sanctions may be at its apex now. The blockade should not be pursued to the point of massive starvation of a population that has its own reasons to hate Saddam.

"Sanctions were conceived in piety as a bloodless substitute for war," Robin Renwick, a senior British diplomat, wrote nearly a decade ago in the most balanced study of the subject I know. "Their main effect, however, has invariably been punitive" rather than remedial. "They may weaken the target regime; but they will not necessarily change its behavior."

Strategic bombing has also failed to break civilian morale and to produce political capitulation in past wars. But Saddam's Iraq has nothing to do with Hitler's Germany or Ho Chi Minh's Vietnam. As ludicrous as it sounds, Saddam lacks Hitler's or Ho's claim to political legitimacy and popular support that their populations accorded them. The analogy to keep in mind is Libya and Moammar Gadhafi.

Saddam has tortured and assassinated the religious leaders of the country's Shiite Moslems, who form 50 percent of Iraq's 17 million population. He has tried to exterminate the 20 percent of his people who are Kurdish. Saddam's Takriti clan has abused the Sunni Arab population as well. A bombing campaign that shatters Saddam's military and secret-police apparatus can succeed without necessarily stirring resentment within the Iraqi nation.

Despite expert predictions to the contrary, there was no great outpouring of Arab or even Libyan rage after U.S. warplanes raided Tripoli in April 1986. In the Iraqi conflict, the United States Navy will be able to use its highly accurate, conventionally armed Tomahawk cruise missiles, which were held out of the Libya operation because the then chairman of the Joint Chiefs of Staff, Adm. William Crowe, feared exposing operational details to a still openly hostile Soviet Union.

Saddam's repeated executions of top Iraqi military commanders over the past 15 years show that he worries about his army's loyalty. He should. During the Iran-Iraq war desertion was so serious that Saddam ordered tens of thousands of deserters hiding in Iraqi marshes killed with poison gas.

Air strikes that suppress Saddam's ability to use chemical weapons and break the exposed supply lines of Iraq's occupation army in Kuwait should encourage Iraqi troops to surrender if they know they will be protected from Saddam by the blocking U.S.-Arab force now being built up on the ground.

The Arab participation against Saddam is crucial to the long-term success of Operation Desert Shield. Those who say that the United States cannot and should not keep large numbers of its ground troops in the Arabian Peninsula for more than a few months are right. Bush does not have a long-term military option in that sense.

But Egyptian President Hosni Mubarak does, if Saudi Arabia's understandable concern about hosting a large military presence from an impoverished, much more populous Arab neighbor can be satisfied. A small American presence that performs a command function over an Arab defense force composed almost entirely of Egyptian troops is the key to stability once Saddam's military force has been defanged.

A momentous change in Arab and American attitudes has been largely overlooked in the confusion that Iraq's invasion has produced. For the first time, the United States is ready to commit itself to a major combat role on behalf of Arabs. For the first time, Arab leaders have chosen to stand together to confront the evil in their ranks and not blink it away. The gathering of Saddam, the Palestinian terrorists and Gadhafi on one side defines in stark terms the nature of this conflict and what America and its allies need to do.

The question has been asked before, but it bears repeating at this point: If not now, when?