DIPLOMAT TAKES SEAT IN VIETNAM; EX-POW IS FIRST U.S. AMBASSADOR IN 22 YEARS; MIAS A PRIORITY.

Byline: Associated Press 

On a moonless evening in 1966, an anti-aircraft missile shot down Capt. Pete Peterson's Air Force bomber near Hanoi. That was the beginning of 6-1/2 years in prison, where he was tortured and kept in solitary confinement in a dank cell.

On Friday, Peterson made a euphoric return to Vietnam under very different circumstances. The former POW is now the first U.S. ambassador posted to communist Vietnam, and he says he'll make it a priority to account for soldiers who are still missing in action.

The arrival of Ambassador Peterson, 62, established full diplomatic relations between the former enemies who spent hundreds of thousands of lives and billions in armaments to defeat each other.

He was greeted at the airport with bear hugs, cheers and smiles - a euphoric, heartfelt welcome that was a generation away from the chaos and disgrace that marked the departure of the last U.S. ambassador to Vietnam.

Twenty-two years and 11 days ago, Graham Martin, the American ambassador to South Vietnam, tucked the U.S. flag under his arm, climbed atop the embassy in Saigon and fled the devastated city by helicopter.

``This is a special day for America and Vietnam, the exchange of ambassadors marks the full normalization of our relations,'' Peterson said at Hanoi's sleepy Noi Bai International Airport. ``This is the beginning of a new era of constructive relations.''

About 100 well-wishers, including war veterans and business leaders, met Peterson at the airport. Waving U.S. and Vietnamese flags, the crowd welcomed the ambassador's message that it was time to move forward from the legacy of war.

``The war belongs in the past,'' said former North Vietnam militiaman Mai Van On, who hugged Peterson. ``The Vietnamese people value anything the United States can bring to develop our country.''

The 79-year-old On saved Sen. John McCain, R-Ariz., in 1967 after McCain was shot down over Hanoi.

From the aftermath of Saigon's fall and years of postwar animosity, Peterson hopes to help build on a budding new relationship.

``My mission is to advance U.S. interests in Vietnam, and our highest national priority is to advance the fullest possible accounting for persons missing from the war,'' he said.

Almost 1,600 American servicemen are still listed as missing in action in Vietnam.

Vietnam's leadership and U.S. business groups hope the ambassador will also help boost lagging economic ties.

Peterson's arrival ``affirms that both countries are interested in closing the chapter on the past in order to look toward the future,'' Prime Minister Vo Van Kiet told reporters recently.