Married 32 years, the nuclear physicist and his wife share a typical brick-and-siding home in Northern Virginia, with a big-screen TV in the family room and a bowl of cashews beckoning on the coffee table. A photomontage shows their three sons, dark-haired, handsome and grown. Here's the family on a vacation at Luray Caverns.

Something's missing, though. Where are the wedding pictures? The cute childhood photographs?

All left behind in Baghdad, says Khidhir Hamza, the highest-ranking government scientist to escape from Iraq and live to tell the tale. To take a family album risks being found out as a defector, and death: "You must bring along nothing that could implicate you," he says.

Hamza, 64, has only old passports to document his previous life. One bears a treasured date stamp: Sept. 15, 1995, the day he made it to the United States.

Anybody who wonders why Iraqi scientists have not been cooperating with United Nations inspectors, or how instrumental they are in concealing banned weapons programs, need only consult Hamza. For nearly 20 years he worked to arm the Iraqi regime with atomic weapons, while Hussein denied to the world that he wanted the Bomb. Two years ago he published a book about the Faustian bargain he struck as Hussein's "personal nuclear adviser."

Its title is "Saddam's Bombmaker," and Hamza says on the opening page, "I am lucky to be alive."

Before sliding behind the wheel of his aging American luxury car, Hamza pauses in his driveway. "That house," he says, pointing down the block, "a deputy sheriff." It's security by coincidence, but gives Hamza and his wife, Souham, a measure of comfort.

The defector is highly visible -- he made the rounds on TV and radio yesterday after Secretary of State Colin Powell's U.N. address -- but requests that his home town not be identified, citing "possible enemy resources here." A few years after defecting, he feared that he was being shadowed by an Iraqi agent; a reporter who wanted to interview Hamza at home had to agree to arrive blindfolded.

"We are living normally," he says now. He's been giving speeches, consulting with government officials, meeting with a Hollywood scriptwriter. Sales of his autobiography -- co-written with spy-tale flourish by Washington journalist Jeff Stein -- have accelerated with the tempo of U.S. war drums.

The book's revelations have been invoked repeatedly by the Bush administration as part of the rationale for invading Iraq. Alluding to Hamza, the president said in an October speech to the nation, "Information from a high-ranking Iraqi nuclear engineer who had defected revealed that despite his public promises, Saddam Hussein had ordered his nuclear program to continue."

Bush didn't mention that Hamza effectively retired from Iraq's nuclear program in 1991, then spent the next few years plotting his escape through northern Iraq. To hawks, Hamza qualifies as a smoking gun because he can attest to a historical pattern of deceit. As Powell showed yesterday, multiple defector sources and the cumulative weight of their statements help build the case against Hussein at a time when U.N. inspectors are discovering little in the way of hardware or documents.

In 1995, "as a result of another defector," the United States discovered Hussein's "crash program," initiated after the invasion of Kuwait, to complete a crude nuclear weapon, Powell said yesterday.

"He was referring to me," Hamza says. The crash program goal, he told U.S. intelligence officials, was to rush a nuclear bomb into production, most likely for a doomsday attack on Israel if U.S. forces threatened Saddam's survival.

Baghdad and the Bomb Schooled in the 1960s at the Massachusetts Institute of Technology and Florida State University, Hamza has a doctorate in nuclear physics, an easy command of English, and the ability to deploy an arsenal of frightening technical details about uranium enrichment, aluminum cylinders, centrifuges, diffusion and "dirty bombs." On TV news shows and in congressional hearings, he echoes suggestions that Hussein will possess enough fissile material to make a bomb in two to three years.

Iraq's nuclear capabilities remain a matter of dispute, but Powell could have been summarizing Hamza's book when he declared yesterday, "Saddam Hussein is determined to get his hands on a nuclear bomb." Helping realize that goal -- whether shopping for a reactor in France or securing complicated equipment in Germany -- was Hamza, who writes that it all started in 1972, when he and others "scratched out our first memo for a bomb."

Some of those pioneers were jailed or tortured after questioning Hussein's intentions. The dictator's son-in-law Hussein Kamel was executed when he unwisely returned to Iraq after defecting to Jordan and spilling his guts about banned weapons programs. Kamel was Hamza's boss.

In his speech, Powell suggested that Iraqi officials routinely intimidate scientists or conceal their whereabouts. "A dozen experts have been placed under house arrest, not in their own houses, but as a group at one of Saddam Hussein's guesthouses," he said, with a seemingly sarcastic emphasis on "guest."

So it doesn't surprise Hamza that scientists are not flocking into the arms of the current U.N. inspection team, despite U.S. assurances of asylum. Cooperation is a potential death sentence, he says. "Talking to an Iraqi scientist inside Iraq is an endangerment. Even asking him to talk is an endangerment."

'Saddam and Me' The son of a rice farmer, Hamza was born in 1939, in a village ravaged by disease. "Only five of the 14 children survived," he writes, "and the last one killed my mother in childbirth."

By 1962, thanks to assistance from the Iraqi government, Hamza arrived in Cambridge, Mass., to study nuclear physics -- with the understanding that he had to repay Iraq with one year of service for every year of subsidized schooling.

His book confronts a paradox about Iraq: How did such a cultured, intellectual society end up at the mercy of a fiendish lout like Saddam Hussein? Perhaps the question arises because of the way co-writer Stein decided Hamza should organize the narrative. He recalls making the scientist put two Post-It notes on his computer screen as reminders.

The one on the left said "Me and Saddam." The one on the right said "Saddam and me."

Despite his penchant for numbing technicalities in conversation, Hamza wanted to produce a page-turner. He says he planned to write a book from the day he defected, turning down a CIA resettlement and witness protection program in part so that he could write freely.

The resulting manuscript won a six-figure advance and stirred a film deal thanks, perhaps, to its focus on Hamza's personal life. It details his first carefree eight years in America -- when he quaffed beer, played poker, dated girls, "bought a car and Beach Boys eight-tracks" -- and his return to Iraq, his arranged marriage to Souham. He was 32 and she was not yet 16.

"I chose him," she says, standing near the stove where dinner is simmering. Dressed in a purple top and flowered slacks, she reminds her husband with a fetching smile that he was but one of her "many" suitors.

"Always he was talking about America," she adds, remembering how he said, "Someday I'll take you to America."

See No Evil As a government scientist in Iraq, Hamza piled up prestige and perks, including ranches, trips abroad, fancy cars. The Baath Party purges, the executions and deportations of political enemies -- communists and Shiites -- did not ping his conscience. As long as he wasn't the target, things were fine.

"We turned a blind eye," Hamza says quietly, sitting in his living room. "Yeah, we turned a blind eye but there is actually also nothing we could have done."

And, as he puts it in the book, "I was too old, too comfortable, too scared to risk my wife and children and leave everything behind."

Saddam's invasion of Kuwait, coupled with his demand for a "crash program" aimed at nuking Israel, ultimately pushed Hamza over the edge.

"That told us we were really working in a lunatic asylum," he says.

He eased himself out of the nuclear program, took a university job, and grew rich as an insider in Iraq's stock market. He escaped alone, leaving his family vulnerable for several months, but eventually a CIA "exfiltration" team helped to smuggle them into the Kurdish-ruled north.

"My tortuous journey had a happy ending," Hamza writes. "But I left behind scores of unhappy Iraqi scientists. . . . Most of them, I am sure, would like to get out. It is the civilized world's urgent duty to help them."

The Top Tier In the summer of 1998, when Hamza first went public with his story about Saddam's relentless desire for the Bomb, much of the press ignored him. The country was transfixed by the saga of Bill Clinton and Monica Lewinsky.

But in March 2001, the scientist found himself sitting next to an influential Republican named Richard Perle at a seminar at George Washington University. He briefed Perle, one of the earliest and most vehement proponents of regime change in Iraq, about his past.

"I came away very impressed, thinking this is a sensible, sober fellow," says Perle, chairman of the Pentagon's advisory Defense Policy Board. Hamza said he'd been debriefed only by low-level "civil servants" in the Clinton years. Perle soon introduced the defector to the top tier of the Bush administration, including Secretary of Defense Donald Rumsfeld.

On Tuesday afternoon, Hamza and Perle are sitting side by side in a garish dining room at the Willard Inter-Continental, joining a panel of former arms inspectors and other hawks. They dutifully denounce Saddam Hussein as a dangerous maniac and urge support for an invasion.

Afterward, this odd, portly pair -- Perle the Washington insider, Hamza the former paladin of Saddam's palace -- get down to the details. They delight in swapping the latest intelligence about how Iraq may have modified aluminum tubes to enrich uranium.

It's something of a preview of Powell's U.N. assertions: that those tubes, which Iraq said were for ordinary missiles, were crucial to building a nuclear weapon. "This was part of the deception program," Perle says. Hamza nods in agreement. "I know, I know."

The Marquee Defector Once he dined and drank at Saddam's private club. Now he orders a $4.25 steak sandwich for lunch at a strip mall sub shop. With one son still in college, Hamza lives modestly. For the first time, Souham has taken a job.

He thinks the United States could have lured more high-level scientists from Iraq in the past if they'd treated them more generously, like the Soviet defectors. He summarizes the American attitude as "Tell us what you know, and goodbye, thank you." Because of what he calls "horrible" foul-ups by the INS, he and his family only recently became citizens.

"I'm not suffering financially," Hamza says, but mainly that's because of the book, a recent History Channel documentary and the movie deal. Trying out Hollywood lingo with an Arabic inflection, he says, "Hopefully next month it will get the green light."

Dan Gordon, who scripted "The Hurricane" with Denzel Washington and "Wyatt Earp" with Kevin Costner, has finished the screenplay. Peter Kalmbach, who heads BBC Films in Los Angeles, calls Hamza "a wonderful subject for a film" and describes him as "the smoldering gun."

"The tricky part is casting him. You know, Brad Pitt as an Arab?"

It's doubtful, but would be the perfect ending to this weird story: Saddam's bomb builder becomes an American idol.

"We turned a blind eye," defector Khidhir Hamza says of Saddam Hussein's regime. "Yeah, we turned a blind eye but there is actually also nothing we could have done."Former U.N. weapons inspector Richard Butler, far left, speaks with Hamza before a Senate hearing last year. Hamza's book recounts his life as Hussein's "personal nuclear adviser."