It seems a done deal. Now that U.S. President George W. Bush has given Baghdad an ultimatum — Iraqi leader Saddam Hussein and his sons must leave Iraq within 48 hours or face invasion — and the suggestion of exile rejected, war seems inevitable. The first shot is days, possibly hours, away.

That Saddam would have actually taken the United States up on the offer of exile — a strategy suggested by, among others, a figure no less notable than former Soviet leader Mikhail Gorbachev, who did step down in part to prevent military conflict — was always unlikely. He has miscalculated before.

His departure would have been the dream scenario. There would have been no military action, economic sanctions against Iraq would have been lifted, worries that the country is developing weapons of mass destruction would have dissipated and Saddam could have lived out his days in luxury in some other country.

One would of course prefer that the dictator be brought to justice, but that would have seemed a minor quibble if his ousting could have been achieved without bloodshed.

Now, however, the military option has been given an effective go-ahead. The Bush administration and the government of British Prime Minister Tony Blair have put far too much on the line, both domestically and abroad, to back down now. The Danes, Spaniards, Australians, Poles and Bulgarians are also all on board.

The military operation will probably be brief. Iraq’s army has been devastated by years of economic sanctions and, in any case, is probably not going to fight too hard to defend a doomed cause when confronted by overwhelming force.

What comes after is more problematic. Iraq is a patchwork of hostile ethnic groups, now kept quiet by the iron boot of the Ba’ath party. Enmities among Kurds, Arabs and Shias, and between Muslims and Christians, will have to be taken into account. Iraq’s infrastructure has already collapsed, and will be further devastated by military action.

The population today lives mainly on food doled out by the government, and will need a steady supply of food, now-scarce medicines and guarantees of housing. Otherwise, they will hardly view the foreign troops in their country as liberators — no matter how hated Saddam is.

Other potentially complicating factors are Iran and Turkey. Iranian-backed Shias tried to wrest Eastern Iraq from Saddam immediately after the Gulf War, and forces have already crossed the border.

Turkey — where over 90 percent of the population is against invading Iraq — has its own concerns with the Kurds within its borders and in northern Iraq, fearing they may use the situation to try to establish the independent Kurdistan so feared by Ankara.

Iraq is not Afghanistan. After the Taliban were ousted from power, attempts to stabilize the country were limited to Kabul. The rest of Afghanistan is still run by heavily armed bandits, and heroin production is again soaring. The United States achieved victory. Most of the people of Afghanistan, still struggling to rebuild, did not.

In Iraq, the United States wants, among other things, guaranteed access to the country’s oil. This can only happen with the establishment of long-term stability in Iraq — and that will require intense effort on the part of the United States and other occupying powers after their military operations are through.

Just going in, spraying firepower and killing or capturing Saddam is not enough. What is needed is a serious, solid commitment to the future of Iraq.

And this, we hope, is what the United States plans for the end of its wartime agenda.