The U.S. visit this week by South Korean President Roh Moo Hyun offers yet another opportunity to bemoan the crisis of confidence in our alliance. Anti-American views, particularly among the young, remain widespread in South Korea. On an official level, there are strains over the role of U.S. troops based in Korea and a stark divergence in approaches toward North Korea.

This portrait of a troubled alliance is often contrasted with a supposed golden age in U.S.-Korean relations during the Cold War. But that view obscures a history of sharp disagreement between the two allies. It is a mythical past that stands in the way of repairing our alliance today. In reality, Korean nationalism and American strategic policy goals have often clashed. Differences over North Korea have arisen repeatedly. And anti-Americanism has been a feature of Korean life for decades.

This was true from the earliest postwar days, in a relationship born out of a fateful and poorly considered decision to divide Korea, after decades of Japanese colonial rule, into American and Soviet zones of occupation. Syngman Rhee, South Korea's first leader, was often at odds with his American backers. Washington feared Rhee would provoke a war with the communist North, even after the end of the Korean War.

Relations with Park Chung Hee, who came to power in a military coup in 1961, were even thornier. Park was a fierce Korean nationalist and, according to a close former aide, uncomfortable with Americans. The two countries collided over North Korea policy, economic goals, human rights and democracy.

In the 1970s, South Koreans developed deep doubts about the durability of the alliance, an uneasiness fed by the Vietnam debacle and the withdrawal of U.S. troops from Korea. Park defied U.S. pressure in declaring martial law in 1972, junking the constitution and jailing leading opposition figures. He launched a secret campaign of influence-peddling and bribery of American congressmen to counter U.S. criticism of his policies.

While Park feared abandonment by the United States, North Korea's Kim Il Sung worried that China, after developing ties to Washington, might sell him out. Thus Park, even though he had been the victim of two assassination attempts by North Korea, reached out to Pyongyang. During high-level talks in 1972, there was a remarkable shared belief that the major powers were the obstacle to Korean reunification.

The most alarming sign of an alliance in crisis was Park's dangerous decision to develop nuclear weapons, made in secret in 1971 after Richard Nixon's withdrawal of one of the two American infantry divisions. According to my research, American officials became alarmed over the seriousness of this effort when a young CIA agent provided evidence of a crude design for a nuclear warhead.

In the spring of 1975, my father, the late ambassador Richard Sneider, sent a top-secret cable to Washington calling for an urgent review of the U.S.-South Korean alliance. Korea was "no longer a client state," he wrote, but was "well on its way to middle power status with ambitions for full self-reliance including its own nuclear potential."

Sneider recommended creation of a new partnership, one more akin to our alliances with NATO or Japan. He also pushed for quiet but tough diplomacy to dissuade Park from heading down the nuclear road. That campaign succeeded finally, but not before my father warned Park that the entire security alliance was jeopardized.

Park was assassinated in 1979 by his own intelligence chief, who claimed to have acted at American instigation. The charge was false, but it remains widely believed in Korea. The perilous state of our alliance reached a peak with the Kwangju uprising against military rule the following year, when hundreds of Koreans were killed by troops deployed with the alleged acquiescence of the United States.

Dispelling the myth of the previous golden era in U.S.-Korean relations does not mean that our relations lacked a foundation of shared interest or that the difficulties we face today are not serious. The gap over how to handle the threat from the North is certainly wider and more evident than in the past. And the democratization of South Korea makes our differences visible and harder to manage.

As policymakers from both countries meet this week, they need to take a deep breath and remember that our alliance survived tremendous stresses in the past. The task before us is not to focus on our divergence but to pick up the challenge left unmet 30 years ago -- to define the basis for a long-term relationship that is durable and reciprocal and that finally sheds the shackles of dependency.

His Excellency Sir David Manning, British Ambassador to the United States, delivered the 2006 Frank E. and Arthur W. Payne Distinguished Lecture: "Energy: A Burning Issue for Foreign Policy," on Monday, March 13, 2006 at 4:30 p.m. in the Bechtel Conference Center at Encina Hall.

Sir David Manning has been Her Majesty's Ambassador to the United States of America since September 2, 2003.

Sir David Manning's Biography:

2003 - present: Washington, USA (Ambassador)

2001 - 2003: Foreign Policy Adviser to the Prime Minister

2001: UK Delegation NATO Brussels (Ambassador)

1998 - 2000: Foreign and Commonwealth Office (Deputy Under-Secretary)

1995 - 1998: Tel Aviv, Israel (Ambassador)

1994 - 1995: Foreign and Commonwealth Office (Head of Policy Planning Staff)

1994:UK member of Contact Group on Bosnia (International Conference on Former Yugoslavia)

1993 - 1994: Foreign and Commonwealth Office (Head of Eastern Department)

1990 - 1993: Moscow, Russia (Counselor, Head of Political Department)

1988 - 1990: Counselor on loan to Cabinet Office

1984 - 1988: Paris, France (1st Secretary)

1982 - 1984: Foreign and Commonwealth Office (Deputy Head of Policy Planning Staff)

1980 - 1982: Foreign and Commonwealth Office (Soviet Department, later Eastern Department)

1977 - 1980: New Delhi, India (2nd later 1st Secretary)

1974 - 1977: Warsaw, Poland (3rd later 2nd Secretary)

1972 - 1974: Foreign and Commonwealth Office (Mexico/Central America Department)

1972: Entered Foreign and Commonwealth Office

In the old popular song about the rout by Americans at New Orleans during the War of 1812, the British "ran so fast the hounds couldn't catch 'em." Even allowing for patriotic hyperbole, it can hardly be argued that the British extricated themselves with a great deal of dignity, particularly given that another battle in the same war inspired the American national anthem.

The impact of that defeat on the British national psyche is now obscure, but nearly two centuries later, as the Americans and their British allies seek to extricate themselves from Iraq, the story of how a superpower looks for a dignified way out of a messy and often unpopular foreign conflict has become a historical genre of sorts. As the pressure to leave Iraq increases, that genre is receiving new and urgent attention.

And in the shadow of the bleak and often horrific news emerging from Iraq nearly every day, historians and political experts are finding at least a wan hope in those imperfect historical analogies. Even in the absence of a sudden and dramatic shift on the battlefield toward a definitive victory, there may still be a slight opening, as narrow as the eye of a needle, for the United States to slip through and leave Iraq in the near future in a way that will not be remembered as a national embarrassment.

Most of the recent parallels do not seem to offer much encouragement for a confounded superpower that wants to save face as it cuts its losses and returns home. Among them are the wrenching French pullout from Algeria, the ill-fated French and American adventures in Vietnam, the Soviet humiliation in Afghanistan and the disastrous American interventions in Beirut and Somalia.

Still, there are a few stories of inconclusive wars that left the United States in a more dignified position, including the continuing American presence in South Korea and the NATO peacekeeping mission in Bosnia. But even those stand in stark contrast to the happier legacy of total victory during World War II.

The highly qualified optimism of these experts about what may still happen in Iraq - let's call it something just this side of hopelessness - has been born of many factors, including greatly reduced expectations of what might constitute not-defeat there. The United States already appears willing to settle - as if it were in a relationship that had gone sour but cannot quite be resolved by a walk out the door, punctuated with a satisfying slam.

Alongside the dampening of hopes, there has also been a fair amount of historical revisionism regarding the darker tales of conflicts past: a considered sense that if the superpowers had made different decisions, things could have turned out more palatably, and that they still might in Iraq.

Maybe not surprisingly, Vietnam is the focus of some of the most interesting revisionism, including some of it immediately relevant to Iraq, where the intensive effort to train Iraqi security forces to defend their own country closely mirrors the "Vietnamization" program in South Vietnam. If Congress had not voted to kill the financing for South Vietnam and its armed forces in 1975, argues Melvin R. Laird in a heavily read article in the current issue of Foreign Affairs, Saigon might never have fallen.

"Congress snatched defeat from the jaws of victory by cutting off funding for our ally in 1975," wrote Mr. Laird, who was President Nixon's defense secretary from 1969 to 1973, when the United States pulled its hundreds of thousands of troops out of Vietnam.

In an interview, Mr. Laird conceded that the American departure from Vietnam was not a pretty sight. "Hell, the pictures of them getting in those helicopters were not good pictures," he said, referring to the chaotic evacuation of the American embassy two years after Vietnamization was complete, and a year after Nixon resigned. But on the basis of his what-if about Vietnam, Mr. Laird does not believe that all is lost in Iraq.

"There is a dignified way out, and I think that's the Iraqization of the forces over there," Mr. Laird said, "and I think we're on the right track on that."

Many analysts have disputed the core of that contention, saying that large swaths of the Iraqi security forces are so inept they may never be capable of defending their country against the insurgents without the American military backing them up. But Mr. Laird is not alone in his revisionist take and its potential application to Iraq.

William Stueck, a history professor at the University of Georgia who has written several books on Korea, calls himself a liberal but says he buys Mr. Laird's basic analysis of what went wrong with Vietnamization.

Korea reveals how easy it is to dismiss the effectiveness of local security forces prematurely, Mr. Stueck said. In 1951, Gen. Matthew Ridgeway felt deep frustration when Chinese offensives broke through parts of the line defended by poorly led South Korean troops.

But by the summer of 1952, with intensive training, the South Koreans were fighting more effectively, Mr. Stueck said. "Now, they needed backup" by Americans, he said. By 1972, he said, South Korean troops were responsible for 70 percent of the front line.

Of course, there are enormous differences between Iraq and Korea. Korean society was not riven by troublesome factions, as Iraq's is, and the United States was defending an existing government rather than trying to create one from scratch.

Another intriguing if imperfect lesson can be found in Algeria, said Matthew Connelly, a Columbia University historian. There, by March 1962, the French had pulled out after 130 years of occupation.

That long colonial occupation, and the million European settlers who lived there before the bloody exodus, are major differences with Iraq, Mr. Connelly noted. But there were also striking parallels: the insurgency, which styled its cause as an international jihad, broke down in civil war once the French pulled out; the French, for their part, said theirs was a fight to protect Western civilization against radical Islam.

Like President Bush in Iraq, President Charles de Gaulle probably thought he could settle Algeria in his favor by military means, Dr. Connelly said. In the short run, that turned out to be a grave miscalculation, as the occupation crumbled under the insurgency's viciousness.

Over the long run, though, history treated de Gaulle kindly for reversing course and agreeing to withdraw, Mr. Connelly said. "De Gaulle loses the war but he wins in the realm of history: he gave Algeria its independence," he said. "How you frame defeat, that can sometimes give you a victory."

The Americans in Beirut and the Soviets in Afghanistan are seen, even in the long view, as cases of superpowers paying the price of blundering into a political and social morass they did not understand.

For the Soviets, that mistake was compounded when America outfitted Afghan rebels with Stinger missiles capable of taking down helicopters, nullifying a key Soviet military superiority. "I don't think they had a fig leaf of any kind," said Henry Rowen, a fellow at the Institute for International Studies at Stanford who was assistant secretary of defense for international security affairs from 1989 to 1991. "They just left."

In Beirut, the Americans entered to protect what they considered a legitimate Christian-led government and ended up, much as in Iraq, in the middle of a multipronged civil conflict. In October 1983, a suicide attack killed 241 American servicemen at a Marines barracks, and four months after that, with Muslim militias advancing, President Ronald Reagan ordered the remaining marines withdrawn to ships off the coast, simply saying their mission had changed. The episode has been cited by Vice President Dick Cheney as an example of a withdrawal that encouraged Arab militants to think the United States is weak.

Today, even as expectations for Iraq keep slipping, some measure of victory can still be declared even in a less-than-perfect outcome, said Richard Betts, director of the Saltzman Institute of War and Peace Studies at Columbia. For example, he said, an Iraqi government that is authoritarian but not totalitarian might have to do.

The key point, he said, is that under those circumstances, the outcome "doesn't look like a disaster even if it doesn't look good."