Agent Provocateur

Early in the war, before the arrival of U.S. combat forces, American advisers to the South Vietnamese helped the army of President Ngo Dinh Diem devise new tactics for fighting Vietcong guerrillas with the assistance of American helicopters, potentially a powerful weapon in a guerrilla war. An learned all about the new tactics from South Vietnamese and American sources and conveyed details to his masters in the North. The generals in Hanoi helped Vietcong commanders develop countertactics that were tested in one of the most important battles of the early war, at the village of Ap Bac just 30 miles south of Saigon. In January 1963, Vietcong forces clobbered the South Vietnamese in that engagement, shot down five U.S. helicopters, killed three American advisers and wounded five more. An's information had been critical.

In late 1967, An's masters told him their secret plans to launch the Tet Offensive early in 1968. He thought this was a bad idea -- he doubted the South Vietnamese people would join the "general uprising" the communists hoped the Tet attacks would provoke. But his job was to help prepare for the attacks, so for days he scouted out potential targets in Saigon, looking for soft spots in the city's defenses. He boldly brought his commander into the city and showed him around, introducing him as a bird collector and dealer (An collected birds himself) from out of town. The intelligence they gathered helped the communists infiltrate forces into Saigon for the offensive.

A third key moment came in 1975, when the North Vietnamese doubted they could march to Saigon uncontested. They thought it would take several years longer to lay the groundwork. An helped persuade them that the situation was ripe to take the initiative; of course, he was proved right.

The conquering North Vietnamese marched into Saigon and won a hard-fought victory, but they never really trusted Pham Xuan An. He was "re-educated," used as a consultant to explain American actions, but never entrusted with a serious job. The North Vietnamese must have suspected his revolutionary credentials. They were right to do so. An liked Americans and American ways too much to ever be a loyal Marxist-Leninist.

I returned to Vietnam in 1994 and had two long conversations with An, then frail but still alive to the world around him. He said he was happy to talk but asked me not to quote him by name. I wanted him to discuss the American war and its consequences for Vietnam and for us, but An was bored by those topics. "You won World War III," he said a little impatiently, obviously referring to the Cold War. "So you lost a skirmish here -- so what?"

Was he sad about that outcome? I thought not. An's cause was the unification and independence of Vietnam, not Marxism-Leninism. He had been frustrated by his own fate in the unified Vietnam, but the outcome of "World War III" seemed to suit him fine. An died in September 2006, of emphysema. Nearly 80, he'd been a chain smoker for half a century.

Berman's book appears 32 years after the war, yet, amazingly, adds significantly to our understanding of what happened. Students of American failures -- who have had so much new material to ponder -- will be richly rewarded by reading this book. So will le Carré fans -- not for its style but for its remarkable substance. ·

Robert Kaiser, an associate editor of The Post, was a reporter in its Saigon bureau, 1969-70.