Iraq's new prime minister, Ayad Allawi, has been making the same basic argument for the past two decades that a stable, post-Saddam Hussein government can be built only on salvageable remnants of the old army and civil service. Starting next week, Allawi will have a chance to put that theory into practice.

I've known Allawi since 1991, when he was trying to organize a coup after Hussein's defeat in the Gulf War that year. Here's how he explained his group's strategy to me in one of those early conversations: "We were originally leading members of the Baath Party, so we still have a lot of supporters in the Iraqi establishment. We subscribe to the theory that we can only change the regime through the existing establishment."

Allawi's group was backed through the early 1990s by British intelligence and later by the CIA and many Arab intelligence services. But he was never able to pull off his palace coup. When the United States invaded Iraq last year, it decided to embrace another strategy for rebuilding the country. Rather than working with the Iraqi army and former members of the Baath Party, as Allawi had urged, the Americans decided to start from scratch -- and build a democratic Iraq from the bottom up.

That ambitious U.S. strategy now lies in ruins in the final days before the handover of sovereignty. It was a victim of too much wishful thinking and too little practical planning. Because America had too few troops to maintain security, it could never deliver on its promises to rebuild a prosperous Iraq.

Now the Americans have turned back to their old covert ally, Allawi, backing him as interim prime minister. The hope is that he can use parts of the old power structure to restore security to a country that, over the past year of occupation, has been coming apart at the seams.

A large, round-faced man, the 58-year-old Allawi has the advantage of a stolid imperturbability. Trained as a medical doctor, he seems unfazed by a life of repeated assassination attempts, including one in 1978 that nearly killed him. He's an amiable, somewhat disheveled man who has to be prodded to buy the fancy clothes befitting a politician. Though a practicing Shiite Muslim, Allawi is a secular man with Western tastes. One old friend recalls him fleeing a fancy Ritz-Carlton hotel in Washington to eat at a fast-food restaurant in a mall.

Allawi joined the brutal world of Baathist intelligence as a young man, and there are many stories about his ruthlessness as an operative in Europe during the 1970s. But many of his friends agree with a former CIA station chief who describes him as a "big, strapping bear" who cared little about his own power: "His idea was to bring everyone under the tent, and make sure no one was excluded."

I have talked regularly with Allawi since Saddam Hussein was toppled last April, and I can offer some hints of how he is likely to govern Iraq. The quotes below are drawn from a long e-mail he sent me from Baghdad this week.

Allawi has made a surprisingly fast start since he was named interim prime minister early this month -- issuing almost daily proposals and public statements. Inevitably, he has tried to distance himself from his U.S. patrons -- suggesting he may impose martial law and announcing plans to fold the Americans' cherished new security force, the Iraqi Civil Defense Corps, into a revived Iraqi army.

Allawi explained his decision to disband the corps this way: "We need to regroup, reorganize and pool our resources in a fashion which is fully understood by the Iraqi culture. We are Iraqis -- not Americans or Swedes." A mistake of American postwar planning, he said, was in "sometimes presenting models of governance which are suitable to the U.S., but don't meet the requirements and culture of Iraq."

As a former Baathist, Allawi hopes he can persuade the Baath regime in Syria to help police Iraq's borders. And he said he has sent letters to all his neighbors "asking for their support and understanding and inviting them for constructive dialogue." He has contacts from his old, coup-plotting days with the governments of Turkey, Jordan, Egypt, Syria and Saudi Arabia. "I intend to make use of these relationships," he said.

Allawi's appeal, and also his liability, is that he will govern Iraq as a strongman. His biggest problem these next few months will be staying alive, in the face of death threats. His only real protection will be the support of other Iraqis. In that sense, for all the U.S. troops who will remain after Wednesday's handover, Iraq's fate will really be in the hands of Iraqis once again.

davidignatius@washpost.com