One of the most apt - and worrisome - warnings about the future of Iraq may be the successful CIA coup that once toppled the regime next door.
In Iran, the United States overthrew a prime minister and reinstalled Shah Reza Pahlavi, ushering in a quarter-century of dictatorship that itself was swept away by an anti-US Islamic revolution in 1979. Iran is one of several examples that today highlight the unpredictable risks of regime change and nation-building.
From the postwar occupations of Japan and Germany - which are cited by the Bush administration as models for Iraq - to the far less glowing recent examples in Somalia and Afghanistan, analysts say America has again failed to learn the lessons of its past. Nation-building is always hard - and almost never successful when done on the fly, on the cheap, or under fire, they say.
Despite ardent efforts by the US, Iraq is facing all three challenges. But with final results so uncertain the Iran case waves like a warning flag.
"It is not far-fetched to draw a line from [the Iran coup] through the Shah's repressive regime and the Islamic revolution to the fireballs that engulfed the World Trade Center in New York," says Stephen Kinzer in his book "All the Shah's Men."
First, some history: In 1953, fear of a communist takeover led the US to engineer the overthrow of Prime Minister Mohammad Mossadeq. Historians today cite new documents that show those fears were exaggerated. The CIA coup had also been encouraged by British officials, seeking revenge against Mr. Mossadeq, for wresting control of Iran's oil industry from Britain two years earlier.
"The US went in thinking they were doing everybody a favor and thinking this was a clear way to protect American interests," says Malcolm Byrne, deputy director of the National Security Archive at George Washington University.
"In fact, within a generation all the fears [of an anti-American takeover] that motivated the move had come to pass," says Mr. Byrne, coeditor of a new volume about the coup based on newly declassified US documents. The 1979 Islamic revolution was "exactly what [US coupmakers] had tried to avoid."
While working to avoid such a stark reversal in Iraq's future, US officials don't look to Iran. They cite examples of postwar reconstruction in Germany and Japan in the 1940s. But to get it right half a century ago, US occupation authorities prepared diligently and kept control for years, historians say. They built upon political foundations that existed in prewar Germany and Japan; they committed far more troops and vast funds; and, perhaps most important, they faced no armed resistance.
Not one US soldier was killed in either occupation. By contrast in Iraq, since Baghdad fell to US troops on April 9, 2003, more than 620 uniformed Americans have died.
"The Germans recognized that they were defeated," says Charles Maier, a professor of German history at Harvard. "Even the hardcore Nazis understood that they were in no position to take on the occupying powers."
The time frame was also far more forgiving than in Iraq. The Western allies in Germany kept residual rights until 1955, even after handing political power to the Federal Republic of Germany in 1949.
"We were far better prepared for the occupations of Germany and Japan," says Professor Maier. "We set up schools for civil administrators from 1942 on. Here [in Iraq] we've been drawing upon reservists who didn't expect this duty and were not trained for it." Dealing with an insurgency during occupation is not new, though the last time the US faced such a case was in the Philippines more than a century ago, from 1898 to 1902. "It was a bloody mess" trying to stamp out a pro-independence insurrection, says Maier. Nation building and democracy were not necessarily part of that colonial equation, and the Philippines weren't given self-rule for nearly 50 years.
Like Germany, no such insurgency existed in Japan, where the nature of the defeat helped US Army Gen. Douglas MacArthur direct Japan's resurrection.
"In Japan the psychological shock ... of the emperor's admission of Japan's defeat can't be underestimated," says John Swenson-Wright, a Japan specialist at Cambridge University in England. "You had a population that had been so deflated so dramatically, and had seen the symbol of the state so clearly admitting what was inconceivable up to that date. That doesn't apply to Iraq, where there has been no acceptance by the old regime of defeat."
The apparent lack of a master plan in Iraq is also in stark contrast to US efforts in Germany and Japan.
"It partly reflects a confusion over objectives: In Japan, defeating the enemy was the single, clear, unambiguous objective," says Mr. Swenson-Wright. "In the run-up to the war in Iraq, it wasn't clear if this was regime change, democratization, decapitation to get rid of Saddam Hussein himself, or dealing with weapons of mass destruction."
The difficulties are compounded by the lack of resources for such ambitious aims in Iraq, relative to the troops and cash expended on Germany and Japan.
"To really do nation-building right, it takes a national commitment, because it's going to take money, people, and time," says Conrad Crane, director of the US Army Military History Institute in Carlisle, Pa. Those conditions were met after World War II, because Americans feared a return of the kind of militarism in Germany and Japan that led to the war, as well as the spread of communism.
The Allies sent 40 military divisions against Germany; the Soviets millions more troops. General MacArthur occupied Japan with 23 divisions, or more than half a million troops. In 1950, on the eve of the Korean War, at least four divisions remained in Japan - "more than we fought the Iraq war with," notes Mr. Crane.
While US forces are far more efficient fighters today, "peacekeeping still remains a very boot-intensive, ground force enterprise," says Crane. Today's overall military forces are much smaller, but cash earmarked for Iraq remains a fraction of that spent after World War II.
The Marshall Plan for Germany, by one estimate, amounted to 3 percent of US GNP for several years. "Today, it would be like our whole defense budget being applied to nation-building," says Crane. "It was a major expenditure, but everybody supported it."
Lack of resources is also being felt in another recent theater of battle - Afghanistan. Soon after US forces disposed of the Taliban regime in late 2001, donors from around the world pledged $18 billion to rebuild.
But little of that cash has been disbursed, as that nation-building exercise took second place to Iraq. US Special Forces hunting Osama bin Laden were redirected to Iraq to hunt for Mr. Hussein; resources, cash, and goodwill for Afghanistan dried up accordingly.
"Ultimately, it comes down to the funding in Afghanistan that wasn't spent," says Julie Sirrs, a former analyst on Afghan and Pakistani affairs for the US Defense Intelligence Agency. "Afghanistan has always been a sideshow [to Iraq] for the administration."
How neglected is the former Taliban-Al Qaeda stronghold? An $87 billion October 2003 spending bill for "Iraq and Afghanistan" reconstruction set aside only 1 percent for Afghanistan.
Late last month, NATO agreed to add 3,500 troops to the 6,500-strong peacekeeping force on the ground, although parliamentary elections have now been delayed until April 2005. But those forces are limited to Kabul; struggling Afghan officials are begging for more.
And there is a further "intangible" cost stemming from Iraq, says Ms. Sirrs. "The US unilateral effort in Iraq has turned a lot of countries away from other US priorities, including Afghanistan," she says.
While nation building has rarely succeeded on the cheap, it has been even more rarely achieved while fighting insurgents. The dangers of underestimating the magnitude of resistance - the most corrosive dynamic in Iraq, experts agree - may be drawn from Somalia.
US marines stormed the beaches of Mogadishu in December 1992 to break the grip of Somali warlords and ease a famine, in what was billed as the first humanitarian intervention after the cold war.
Instead of prevailing, the aid mission turned into an ever-widening US and UN nation-building enterprise. To avenge the deaths of UN peacekeepers by one warlord's clan, US forces took sides in Somalia's internal power struggle.
Months later, after losing 18 US Army Rangers to Somali gunmen in the fiercest firefight since the Vietnam War, the US decided to pull out. The UN left too, abandoning Somalia for good.
"[The US] didn't realize that even though Somalis were among themselves very atomized, against an outsider they often shared resentment, resistance, and suspicion," says Jonathan Stevenson, author of "Losing Mogadishu: Testing US Policy in Somalia."
"The same thing has happened in Iraq," says Mr. Stevenson, an analyst at the International Institute of Strategic Studies in London. "Just as merely providing aid and alleviating a little bit of suffering in Somalia did not establish ... the goodwill of the foreigner, neither did taking out Saddam in Iraq durably establish the goodwill of the [US] occupier."
America's inconsistent record of nation-building - a mission that Mr. Bush rejected for US troops while campaigning in 2000 - may reflect a broader global disconnect.
"There's this liberal universalist assumption that afflicts the US when it intervenes, that by starkly demonstrating the virtues of American political standards, or market democracy, people from other cultures are going to appreciate them as much as we do," says Stevenson. "This is not the case."
May 7-8, 1945: Germany surrenders.
June 5: Allies assume authority over Germany.
Aug. 15: Japan surrenders.
Sept. 1: US occupies Japan, aided by British Commonwealth forces.
April 10, 1946: Japan holds its first postwar elections.
1946 - 1947: US pours in food aid to ward off Japanese famine.
1948 - 1951: Marshall Plan aids in rebuilding Germany.
Aug. 14, 1949: Allies allow first postwar national elections in Germany.
April 1952: Japan regains sovereignty.
May 1955: Germany regains sovereignty.