When Secretary of State Hillary Rodham Clinton was in Hawai'i a couple of weeks ago, like many visitors she went to the USS Arizona Memorial to pay her respects to the 1,177 sailors and Marines who died in that battleship sunk during the Japanese surprise attack on Pearl Harbor on Dec. 7, 1941.

Later, she told an audience of Americans and Asians: "As we were leaving the memorial, Lt. Gen. (Daniel) Darnell told me that he had recently hosted officials from Vietnam." Darnell, deputy commander of Pacific Command, had said that on the launch waiting to take the Vietnamese back to shore, the Navy had flown a Vietnamese flag.

"It was a stunning moment," Clinton said, "stunning on both sides, certainly stunning for our Vietnamese visitors, and stunning for the United States. What other country would do that?

"What other country applauds the success, the prosperity, and development of former enemies, of competitors, of those who have different systems and different cultures and different points of view?"

What other country, indeed?

This American trait, however, is at once a strength and a weakness.

The strength is that Americans seem willing to put the past behind them. Americans fought the British in the Revolution and the War of 1812, yet consider the British today to be the closest of allies. Americans fought the Germans in World Wars I and II, yet they are strong allies today. Americans fought the Japanese in World War II, yet see Japan today as a key ally despite disputes over U.S. bases. The U.S. fought the Chinese in the Korean War, yet is seeking peaceably to resolve differences with China today.

In Vietnam, where Americans fought from 1954 to 1973, the U.S. Air Force plans to mount a medical and engineering operation in May called Pacific Angel. It will be centered in Can Tho, in the Mekong Delta where fierce fighting took place. This will be the second Pacific Angel, the first having been last year in Quang Tri, near what had been the demilitarized zone dividing North and South Vietnam.

About 40 Americans organized by the 13th Air Force at Hickam Air Force Base will work alongside Vietnamese military medics, government agencies, and nongovernmental organizations for seven days and are expected to treat several thousand Vietnamese. American engineers plan to do plumbing, electrical and structural work on schools and clinics.

Contrast that with the unabated, centuries-old hostility between Koreans and Japanese or the continuing, emotional tensions between Indians and Pakistanis or the unrelenting, mindless threat to Israel from the Arab nations. Even Franco-German relations are fragile despite their membership in the European Union.

The weakness is that sometimes Americans forget the lessons of history. Perhaps most evident is similar reaction to Japan's attack on Pearl Harbor and to the terrorist attacks of Sept. 11, 2001. Just as few Americans ever thought Japan could attack the U.S., so Americans 60 years later were dumbfounded when Arab terrorists struck New York and Washington.

An exception among Americans: those who were treated brutally as German, Japanese, Chinese, North Korean or Vietnamese prisoners of war. Many, understandably, have been unable to forgive or forget what their captors did to them.

Even so, President George H.W. Bush reflected the American spirit when he spoke to survivors of Pearl Harbor: "I have no rancor in my heart toward Germany or Japan — none at all. And I hope, in spite of the loss, that you have none in yours."

"World War II is over," said the former president, a Navy pilot shot down during the war. "It is history. We won. We crushed totalitarianism — and when that was done, we helped our enemies give birth to democracies.

"We made our enemies our friends."