Chapter 1 Going to B Hanoi remembers the war, but mainly Hanoi forgets. There seems to be no end to the construction boom. In the city''s upscale neighborhoods, Vietnam''s nouveaux riches build themselves gaudy mansions with Roman balconies, Doric and Corinthian pillars, and classical fountains and statuary. Luxury high-rise apartment buildings spring up overnight. Many of these monuments to the new prosperity have English names--the Lancaster, the Gardenia, Goldmark City, the Skylake. Towering over a cloverleaf intersection by the rust-brown crawl of the Red River is the Sunshine Riverside, the name revolving in rainbow colors on a giant LED display at penthouse level. Other complexes, like the D''Le Roi Soleil, pay oblique homage to Vietnam''s French colonial heritage. By the end of the second decade of the twenty-first century, the politburo of the Vietnamese Communist Party had designated tourism a "spearhead industry," and Vietnam was welcoming close to 18 million foreign visitors a year.

About half come from East Asia. Among the Westerners, two groups predominate: twentysomething backpackers and retirees, most of them old enough to remember the war. They come to see Vietnam, the country, and to look for echoes of Vietnam, the war. Sometimes it can seem that on any given day most of them are strolling around Hanoi''s Hoan Kiem Lake, the Lake of the Restored Sword, the beautiful though polluted heart of the city''s tourist district, stopping in at the Temple of the Jade Mountain and taking photos of the elderly ladies doing their morning tai chi exercises. Dodging the motorbikes in the labyrinthine "36 Streets" of the Old Quarter, they book package tours to the beautiful karst archipelago of Ha Long Bay and homestays in the stilt-house villages of the ethnic minorities whom the French and the Americans called the Montagnards, the mountain people. They squat on blue plastic stools beneath the caged songbirds to slurp up pho, Vietnam''s classic noodle soup, and shop for silks and silver and revolutionary kitsch--Ho Chi Minh T-shirts and refrigerator magnets, faux Zippo lighters and dog tags, reproductions of wartime propaganda posters. Some of the tourists take a cyclo ride for a couple of miles to join the early morning throngs of uniformed soldiers and schoolchildren and young pioneers in red neckerchiefs lined up to visit the monolithic granite mausoleum of Ho Chi Minh on Ba Dinh Square, which is ringed by the elegant colonial-era buildings, painted mustard yellow and salmon pink, that house the offices of party and government. Inside, they shuffle around the icy crypt for a brief glimpse of the waxy corpse of the iconic leader of the Vietnamese revolution, preserved thanks to the skills of Russian embalmers, who had perfected their art on Lenin.

The spectacle would have appalled Uncle Ho, a frugal man who left written instructions that his body should be cremated, his ashes divided into three parts and scattered in the north, south, and center of the country, but with neither monument nor grave marker. Some visitors take a short walk to the Museum of Military History, with its totemic display of crashed American airplanes and the antiaircraft guns that brought them down. Nearby, running parallel to a stretch of the main north-south railroad where the modest houses and shops crowd in close enough to the tracks for residents to reach out and shake hands with the passengers, is a long street called Ly Nam De, named for a sixth-century emperor who is regarded as one of the earliest champions of Vietnam''s independence. For the most part, Ly Nam De looks much like countless other streets in modern Hanoi. The tree-shaded sidewalks are an obstacle course of parked motorbikes. The Ficus Suites offer luxury rental apartments for expats. Farther down the block are Annie''s Lingerie and the Laura Beauty Spa. But Ly Nam De is also a military enclave, resonant with history.

There are two barracks of the People''s Army of Viet Nam, the PAVN, and the offices of the Army Publishing House. Gen. Nguyen Chi Thanh, who commanded military operations in the South from September 1964 until his death in July 1967, lived at number 34, which is now home to the Viet Nam War Veterans Association. Number 83 houses the Military Library, and while there is no public monument or memorial plaque, the building was the setting for one of the most consequential events in Vietnam''s history, a secretive meeting in May 1959, convened on orders from the politburo, that prefigured the entire logic of what Vietnamese call the American War. For many years after the fall of Saigon, the conventional wisdom was that the success of the Vietnamese revolution could be attributed primarily to two men, each with his own distinctive charisma and legend. Ho Chi Minh, "He Who Enlightens," founder of the Indochinese Communist Party, with his wispy chin-beard, benign smile, and avuncular manner, was its inspiration. Gen. Vo Nguyen Giap was the military genius who had engineered the decisive victory over the French at Dien Bien Phu in 1954 and who, for decades until his death in 2013, at the age of 102, charmed foreign visitors with his urbane manners and impeccable French.

But the story is more complicated and in many ways much darker. By 1959, other powerful voices had risen to prominence in the Vietnamese Workers Party--known after reunification as the Vietnamese Communist Party--contesting and eventually eclipsing the paramount authority of Ho and Giap. Two men were central to this less visible power structure. The senior of the two was Le Duan, a member of the politburo, a gaunt and dogmatic figure distinctly lacking in charisma. On the military side, there was his close political ally and fellow politburo member Nguyen Chi Thanh, the head of the PAVN''s general political department and the only general promoted to share Giap''s five-star rank. Following the Leninist precepts of democratic centralism, the party took great pains to present a unified public face that masked its internal debates and the often brutal silencing of dissent. American policy makers, and the first generation of postwar historians, were generally aware of two camps that could be classified, at the risk of oversimplification, as moderates and hard-liners. The faction headed by Ho and Giap favored a protracted armed struggle combined with patient diplomacy and negotiations; the other, headed by Le Duan, advocated bold acts of revolutionary violence that would trigger mass uprisings as the key to national liberation.

Sometimes these factions were respectively categorized as pro-Soviet and pro-Chinese, though those allegiances shifted at different times, and in general the party as a whole succeeded in holding on to the support of both Communist powers while never allowing them to dictate Vietnam''s war strategy. The two factions were defined by differences of temperament and ideology, each camp reading in its own way the shifting currents of global politics in the Cold War. But the clashes were also deeply rooted in geography and above all in the personal experiences and local loyalties of Le Duan and Thanh during the war against the French. The first signs of friction had been apparent as early as 1951, and they grew bitter with the 1954 Geneva Accords, which split Vietnam in two after the collapse of French colonial rule in Indochina. There was fierce argument in Geneva about where the country should be divided. Negotiators for the North--the Democratic Republic of Viet Nam--initially demanded the thirteenth parallel, which would have given them control over two-thirds of the country. Ho Chi Minh was prepared to settle for the sixteenth. But both the Soviet Union, emerging at the time from the darkness of Stalinism, and China, still reeling from the Korean War, pressed him to make further concessions, anxious to prevent the hostilities in Vietnam from triggering a wider conflict.

In the end, Ho was forced to accept the seventeenth parallel, which split the country into two more or less equal halves. The demilitarized zone between them, the DMZ, would roughly track this line of latitude, extending for five kilometers on either side of the meandering Ben Hai River at the northern edge of Quang Tri province. The distance between two lines of latitude is only fifty-nine miles, but these particular miles had enormous significance for how the American war in Vietnam would be fought. Drawing the line at the seventeenth parallel ceded to the southern government of Ngo Dinh Diem the ancient imperial capital of Hue as well as the city of Danang, with its deepwater harbor. It also gave Diem control of the vital east-west highway, Route 9, which ran parallel to the southern edge of the DMZ. Completed by the French in 1930, it was the only direct connection between the Mekong River on the Thai-Lao border and the South China Sea, which Vietnamese call the East Sea. Vietnam is a long, skinny S-shaped country, and Route 9 crossed it at its narrowest point and thus the easiest for the South to defend against incursions. In places, the mountainous Lao border is not much more than thirty miles from the ocean, and the coastal plain, the fertile rice-growing area that is home to most of the population, is sometimes only ten or fifteen miles wide, which made it uniquely vulnerable to attack from the western mountains of Quang Tri and its neighbor to the south, Thua Thien.

The location of the DMZ was a stinging personal affront both to Le Duan and to Nguyen Chi Thanh, because these were their home provinces, and they had commanded local revolutionary forces there during the war against the French. Both men had humble origins. Le Duan was from the outskirts of the town of Dong Ha, in Quang Tri, just below the DM.