It will be two or three weeks, we read in the papers, before a land operation is launched for the liberation of Kuwait. Let us put the interim period to good use here at home. It is time for some hard thinking on what comes next.

When this all began, back in August, there was no time for sober reflection on long-range consequences. President Bush had to act. He was damned if he intervened; he was damned if he did not intervene. He chose the first course, and he chose rightly.Now we are well embarked upon a war whose ends cannot be clearly foreseen. It is universally assumed - and the assumption seems sound - that the allied coalition will "win" the war. What is not so clear is what we will have won, or at what price.

Why are we there? It may be useful to reflect upon the reasons the people have been given. We are there:

- To demonstrate to the world that naked aggression will not go unpunished.

- To liberate Kuwait and to restore its legitimate government.

- To protect a vital national interest in access to Middle Eastern oil at a reasonable price.

- To carry out a mandate of the United Nations, expressed in Resolution 678, authorizing member states to use "all necessary means" to achieve the unconditional withdrawal of Iraqi forces from Kuwait.

- To set in motion a process that will lead to what the president calls a New World Order in the area.

These are the ostensible reasons. It will be seen that some of these reasons are lofty, and some are not. Western nations have not consistently leaped to the punishment of aggression - not in Tibet, not in Afghanistan - and we have lately engaged in a little aggression ourselves. The restoration of the emir of Kuwait to his dynastic throne is not a goal worth a drop of American blood.

But underlying these ostensible reasons was another argument. It proved crucial during the somber debate that occupied Congress in early January. This was the conviction that Saddam Hussein could not be left free to terrorize the Middle East with nuclear weapons. What now may be said of this implied but unstated justification for war?

For the sake of appearances, the United States must maintain a solemn pretense that we act merely as an obedient member of the United Nations. We are there to carry out its resolutions. There were 12 such resolutions in all, and all of them stop with the liberation of Kuwait.

It has to be kept in mind that the removal of Saddam never has been an announced aim of the United Nations. It had better not become openly an aim of the allied coalition either. Arab members of the coalition would not agree to any such action.

Moreover, we have reason to believe that Iraq's capacity for developing nuclear weapons has been greatly damaged if not altogether nullified. It is entirely plausible that a defeated Saddam, bearing sole responsibility for the disaster he has inflicted upon his people, could not long survive their resentment. At least for now, let us quiet the bombastic rhetoric about trying Saddam for war crimes. In a few months he may not greatly matter.

Eventually, for good or ill, this war will end as all wars end. Both sides will mourn their dead. Everyone will set to work cleaning up the mess.

Do we have any plan for victory? Under a New World Order, how do we reach agreement on the rights of Israelis and the needs of the Palestinians? What new relationships do we envision with Syria, with Jordan, with Iran? Once Kuwait is liberated, what American presence is to remain? For how long? Is the embargo against Iraq to be lifted? Under what conditions?

These are deeply troubling questions. They have yet to be thoughtfully addressed. Bush has demonstrated great skill in welding together the allied coalition. As leader of the free world, he will face an equally difficult task. Having won the war, he must not lose the peace.