He had plenty of time to think in the following months while recuperating in a military hospital in Hawaii. Among other things, he promised himself that, "If I'm ever in a position to say what I think is right, I will. . . . I don't care what happens to my career."

That time has arrived.

Over the past year, the retired Marine Corps general has become one of the most prominent opponents of Bush administration policy on Iraq, which he now fears is drifting toward disaster.

It is one of the more unusual political journeys to come out of the American experience with Iraq. Zinni still talks like an old-school Marine -- a big-shouldered, weight-lifting, working-class Philadelphian whose father emigrated from Italy's Abruzzi region, and who is fond of quoting the wisdom of his fictitious "Uncle Guido, the plumber." Yet he finds himself in the unaccustomed role of rallying the antiwar camp, attacking the policies of the president and commander in chief whom he had endorsed in the 2000 election.

"Iraq is in serious danger of coming apart because of lack of planning, underestimating the task and buying into a flawed strategy," he says. "The longer we stubbornly resist admitting the mistakes and not altering our approach, the harder it will be to pull this chestnut out of the fire."

Three years ago, Zinni completed a tour as chief of the Central Command, the U.S. military headquarters for the Middle East, during which he oversaw enforcement of the two "no-fly" zones in Iraq and also conducted four days of punishing airstrikes against that country in 1998. He even served briefly as a special envoy to the Middle East, mainly as a favor to his old friend and comrade Secretary of State Colin L. Powell.

Zinni long has worried that there are worse outcomes possible in Iraq than having Saddam Hussein in power -- such as eliminating him in such a way that Iraq will become a new haven for terrorism in the Middle East.

"I think a weakened, fragmented, chaotic Iraq, which could happen if this isn't done carefully, is more dangerous in the long run than a contained Saddam is now," he told reporters in 1998. "I don't think these questions have been thought through or answered." It was a warning for which Iraq hawks such as Paul D. Wolfowitz, then an academic and now the No. 2 official at the Pentagon, attacked him in print at the time.

Now, five years later, Zinni fears it is an outcome toward which U.S.-occupied Iraq may be drifting. Nor does he think the capture of Hussein is likely to make much difference, beyond boosting U.S. troop morale and providing closure for his victims. "Since we've failed thus far to capitalize" on opportunities in Iraq, he says, "I don't have confidence we will do it now. I believe the only way it will work now is for the Iraqis themselves to somehow take charge and turn things around. Our policy, strategy, tactics, et cetera, are still screwed up."

'Where's the Threat?'

Anthony Zinni's passage from obedient general to outspoken opponent began in earnest in the unlikeliest of locations, the national convention of the Veterans of Foreign Wars. He was there in Nashville in August 2002 to receive the group's Dwight D. Eisenhower Distinguished Service Award, recognition for his 35 years in the Marine Corps.

Vice President Cheney was also there, delivering a speech on foreign policy. Sitting on the stage behind the vice president, Zinni grew increasingly puzzled. He had endorsed Bush and Cheney two years earlier, just after he retired from his last military post, as chief of the U.S. Central Command, which oversees operations in Iraq.

"I think he ran on a moderate ticket, and that's my leaning -- I'm kind of a Lugar-Hagel-Powell guy," he says, listing three Republicans associated with centrist foreign policy positions.

He was alarmed that day to hear Cheney make the argument for attacking Iraq on grounds that Zinni found questionable at best:

"Simply stated, there is no doubt that Saddam Hussein now has weapons of mass destruction," Cheney said. "There is no doubt that he is amassing them to use against our friends, against our allies, and against us."

Cheney's certitude bewildered Zinni. As chief of the Central Command, Zinni had been immersed in U.S. intelligence about Iraq. He was all too familiar with the intelligence analysts' doubts about Iraq's programs to acquire weapons of mass destruction, or WMD. "In my time at Centcom, I watched the intelligence, and never -- not once -- did it say, 'He has WMD.' "

Though retired for nearly two years, Zinni says, he remained current on the intelligence through his consulting with the CIA and the military. "I did consulting work for the agency, right up to the beginning of the war. I never saw anything. I'd say to analysts, 'Where's the threat?' " Their response, he recalls, was, "Silence."

Zinni's concern deepened as Cheney pressed on that day at the Opryland Hotel. "Time is not on our side," the vice president said. "The risks of inaction are far greater than the risks of action."

Zinni's conclusion as he slowly walked off the stage that day was that the Bush administration was determined to go to war. A moment later, he had another, equally chilling thought: "These guys don't understand what they are getting into."

Unheeded Advice

This retired Marine commander is hardly a late-life convert to pacifism. "I'm not saying there aren't parts of the world that don't need their ass kicked," he says, sitting in a hotel lobby in Pentagon City, wearing an open-necked blue shirt. Even at the age of 60, he remains an avid weight-lifter and is still a solid, square-faced slab of a man. "Afghanistan was the right thing to do," he adds, referring to the U.S. invasion there in 2001 to oust the Taliban regime and its allies in the al Qaeda terrorist organization.

But he didn't see any need to invade Iraq. He didn't think Hussein was much of a worry anymore. "He was contained," he says. "It was a pain in the ass, but he was contained. He had a deteriorated military. He wasn't a threat to the region."

But didn't his old friend Colin Powell also describe Hussein as a threat? Zinni dismisses that. "He's trying to be the good soldier, and I respect him for that." Zinni no longer does any work for the State Department.

Zinni's concern deepened at a Senate hearing in February, just six weeks before the war began. As he awaited his turn to testify, he listened to Pentagon and State Department officials talk vaguely about the "uncertainties" of a postwar Iraq. He began to think they were doing the wrong thing the wrong way. "I was listening to the panel, and I realized, 'These guys don't have a clue.' "

That wasn't a casual judgment. Zinni had started thinking about how the United States might handle Iraq if Hussein's government collapsed after Operation Desert Fox, the four days of airstrikes that he oversaw in December 1998, in which he targeted presidential palaces, Baath Party headquarters, intelligence facilities, military command posts and barracks, and factories that might build missiles that could deliver weapons of mass destruction.

In the wake of those attacks on about 100 major targets, intelligence reports came in that Hussein's government had been shaken by the short campaign. "After the strike, we heard from countries with diplomatic missions in there [Baghdad] that the regime was paralyzed, and that there was a kind of defiance in the streets," he recalls.

So early in 1999 he ordered that plans be devised for the possibility of the U.S. military having to occupy Iraq. Under the code name "Desert Crossing," the resulting document called for a nationwide civilian occupation authority, with offices in each of Iraq's 18 provinces. That plan contrasts sharply, he notes, with the reality of the Coalition Provisional Authority, the U.S. occupation power, which for months this year had almost no presence outside Baghdad -- an absence that some Army generals say has increased their burden in Iraq.

Listening to the administration officials testify that day, Zinni began to suspect that his careful plans had been disregarded. Concerned, he later called a general at Central Command's headquarters in Tampa and asked, "Are you guys looking at Desert Crossing?" The answer, he recalls, was, "What's that?"

The more he listened to Wolfowitz and other administration officials talk about Iraq, the more Zinni became convinced that interventionist "neoconservative" ideologues were plunging the nation into a war in a part of the world they didn't understand. "The more I saw, the more I thought that this was the product of the neocons who didn't understand the region and were going to create havoc there. These were dilettantes from Washington think tanks who never had an idea that worked on the ground."

And the more he dwelled on this, the more he began to believe that U.S. soldiers would wind up paying for the mistakes of Washington policymakers. And that took him back to that bloody day in the sodden Que Son mountains in Vietnam.

A Familiar Chill

Even now, decades later, Vietnam remains a painful subject for him. "I only went to the Wall once, and it was very difficult," he says, talking about his sole visit to the Vietnam Veterans Memorial on the Mall. "I was walking down past the names of my men," he recalls. "My buddies, my troops -- just walking down that Wall was hard, and I couldn't go back."

Now he feels his nation -- and a new generation of his soldiers -- have been led down a similar path.

"Obviously there are differences" between Vietnam and Iraq, he says. "Every situation is unique." But in his bones, he feels the same chill. "It feels the same. I hear the same things -- about [administration charges about] not telling the good news, about cooking up a rationale for getting into the war." He sees both conflicts as beginning with deception by the U.S. government, drawing a parallel between how the Johnson administration handled the beginning of the Vietnam War and how the Bush administration touted the threat presented by Iraqi weapons of mass destruction. "I think the American people were conned into this," he says. Referring to the 1964 Gulf of Tonkin incident, in which the Johnson administration claimed that U.S. Navy ships had been subjected to an unprovoked attack by North Vietnam, he says, "The Gulf of Tonkin and the case for WMD and terrorism is synonymous in my mind."

Likewise, he says, the goal of transforming the Middle East by imposing democracy by force reminds him of the "domino theory" in the 1960s that the United States had to win in Vietnam to prevent the rest of Southeast Asia from falling into communist hands.

And that brings him back to Wolfowitz and his neoconservative allies as the root of the problem. "I don't know where the neocons came from -- that wasn't the platform they ran on," he says. "Somehow, the neocons captured the president. They captured the vice president."

He is especially irked that, as he sees it, no senior officials have taken responsibility for their incorrect assessment of the threat posed by Iraq. "What I don't understand is that the bill of goods the neocons sold him has been proven false, yet heads haven't rolled," he says. "Where is the accountability? I think some fairly senior people at the Pentagon ought to go." Who? "That's up to the president."

Zinni has picked his shots carefully -- a speech here, a "Nightline" segment or interview there. "My contemporaries, our feelings and sensitivities were forged on the battlefields of Vietnam, where we heard the garbage and the lies, and we saw the sacrifice," he said at a talk to hundreds of Marine and Navy officers and others at a Crystal City hotel ballroom in September. "I ask you, is it happening again?" The speech, part of a forum sponsored by the U.S. Naval Institute and the Marine Corps Association, received prolonged applause, with many officers standing.

Zinni says that he hasn't received a single negative response from military people about the stance he has taken. "I was surprised by the number of uniformed guys, all ranks, who said, 'You're speaking for us. Keep on keeping on.' "

Even home in Williamsburg, he has been surprised at the reaction. "I mean, I live in a very conservative Republican community, and people were saying, 'You're right.' "

But Zinni vows that he has learned a lesson. Reminded that he endorsed Bush in 2000, he says, "I'm not going to do anything political again -- ever. I made that mistake one time."