Saddam Hussein's invasion of Kuwait has done more to change strategic realities than any other military action of the postwar era. It's odd that some Third World dictator could do this. The reason is simple, however. It's oil. He has gotten our attention by putting several divisions adjacent to half the world's oil reserves. Figuratively, he has placed a knife beside our jugular.

Now, what are we going to do about this? The outlines of our policy are emerging. Politically -- a campaign to isolate him and to convey to him that he is playing with fire and could set off a conflagration. Economically -- an effort to squeeze him through sanctions and a blockade. Militarily -- an evolving commitment to defend Saudi Arabia.

Fine. But where does all this lead us? What is the outcome we desire? What is the minimal result we can accept?

It is important that we define our goal for two reasons.

First, it will soon become clear that this campaign against Saddam Hussein is going to be costly. An embargo means we will be driving up the cost of oil and, with it, gasoline at the pump. (Of course, if we have no embargo, Saddam will push up the price -- and enjoy the fruits of expensive gas.) A sustained military buildup in the region would eliminate for the moment the peace dividend everyone has been looking forward to. Finally, if push comes to shove and we end up in a war, the costs will be measured in body bags.

Second, we will soon be hearing the approaching footsteps of people trying to broker compromises. Right now both George Bush and Saddam Hussein sound like they are ready to go to the mat. Soon that will make a lot of people nervous. Arabs from the Persian Gulf are already dickering with Saddam, trying to buy him off. Egypt's President Hosni Mubarak is talking of finding an Arab solution, hinting at a compromise under which Saddam's power would not be not clipped. The embargo will soon prompt others to complain that Kuwait is just a little country far, far away and not worth the effort.

As talk of costs and compromises fill the air, foreign and domestic pressures will mount on the Bush administration to strike a deal. A lot of deals are possible. What can we accept?

The absolute, finite, bottom-line minimum we need to extract from all this is that Saudi Arabia emerges as an independent actor, one able to set its own oil policies without first telephoning Saddam Hussein. We are scrambling now because Saddam threatens to control half the world's oil reserves, either by physically seizing them or by so intimidating the Saudi royal family that it voluntarily accedes to his demands. We cannot tolerate either. Saudi Arabia must remain independent in fact as well as name.

The U.N. Security Council resolution establishes as its bottom line the restoration of the status quo ante. It demands the withdrawal of Iraqi troops from Kuwait and the reconstitution of the Kuwaiti government. But that won't do. The status quo ante can't be completely restored. Saddam's resort to force is history and cannot be wiped from the Saudi psyche. Saddam showed he is both willing and able to resort to force. Those two genies cannot be put back in the bottle and will continue to rattle Saudi Arabia.

Thus, guaranteeing our bottom line boils down to ridding the world of Saddam Hussein or his army. We can tolerate Saddam Hussein without a million-man army; and we can tolerate Iraq's army without Saddam Hussein. But we cannot live with the two together. Getting rid of one or the other is the ideal outcome.

The Iraqi army may decide that, faced with this choice, it would prefer to jettison Saddam. Or the Iraqi public may find the pain of a blockade so displeasing that it will rise up. And, of course, the action of only a single disenchanted person could send Saddam to his ultimate reward.

Clearly, any outcome that leaves Iraq in control of Kuwait is not acceptable. Nor is it acceptable for Iraqi troops to remain positioned to intimidate the Saudis into adopting whatever oil policies Saddam dictates.

This is the defining event of George Bush's presidency. For that matter, this is the defining event of Saddam Hussein's presidency. The outcome will determine which survives politically.

I support the administration's policy and expect that the public will support it as well -- if it understands the stakes involved. Simply put, if we allow Saddam to control half the world's oil reserves, he will control our economy -- determining our rate of inflation, our interest rates, our rate of growth. That cannot be permitted.

Clearly, our deployment involves risks. There is a chance of war. Of course, there's an alternative; we can avoid the risks. We can let Saddam have our jugular.

The writer, a Democratic representative from Wisconsin, is chairman of the House Armed Services Committee.