At the prompting of the Nixon White House, President Nguyen Van Thieu sent South Vietnamese forces into Laos in February 1971, seeking to cut North Vietnamese supply lines to the battlefields in the South. Lam Son 719 was a bloody failure, and it shaped the final phase of America’s Vietnam War. Convinced that the South Vietnamese could never withstand a full-scale offensive, the North Vietnamese leadership committed to a nation-wide attack in early 1972, designed to bring a decisive end to the war. The Easter Offensive, as it is remembered in the West, broke on three fronts in late March 1972, initially with a series of victories by the NVA. President Richard Nixon and his national security advisor, Henry Kissinger, viewed this offensive as a threat to their political and diplomatic objectives, and ordered a massive deployment of US air and naval forces to reinforce the South Vietnamese. In May 1972, Nixon ordered an air offensive against North Vietnam code-named Linebacker to deny resupply to the North Vietnamese forces. The NVA offensive stagnated in late June, setting the stage for negotiations between the US and Hanoi to end the war. Kissinger and Le Duc Tho reached a settlement in early October, but it was rejected by Thieu, forcing the US to renegotiate the treaty. In the end, Nixon directed the most violent air campaign of the war, sending B-52 heavy bombers over Hanoi to coerce the North Vietnamese into accepting the minor changes required for a settlement.

Hanoi entered into negotiations with Washington and Saigon in 1968–9, Chapter 4 explains, but merely to probe and sow division among its enemies. But then unsettling circumstances intervened, including the Sino-Soviet Border War of early 1969; the death a few months later of Ho Chi Minh, who, despite his lack of influence over communist decision-making, remained the venerable face of the Vietnamese struggle for reunification and independence and thus an important public relations tool; and, finally, Nixon’s decisions to “Vietnamize” the anticommunist war effort in the South and then to authorize incursions into Cambodia and Laos. The period 1969–71 was marked by uncertainty and indecisiveness as communist decision-makers reassessed their strategic priorities and placed greater emphasis on alternative modes of struggle. Concerned about potential diplomatic isolation and the loss of Soviet and Chinese support, Le Duan decided to go-for-broke once more. The 1972 Easter Offensive was an abject disaster. Hanoi then tried its luck at the bargaining table, resulting in the Paris peace agreement of 1973 and the suspension of the Fourth Civil War for Vietnam.

Chapter 7 examines the Easter Offensive and the Linebacker I & II air campaigns. When the NVA launched the offensive, the question remained whether the ARVN could incorporate air–ground coordination lessons from Lam Son 719. The ARVN held on two of three fronts but faltered along the demilitarized zone (DMZ). Effective US air power and resolute ARVN forces, coordinated by US military advisors and air liaison officers, held off further NVA advances as the ARVN regrouped to launch a counteroffensive to retake Quang Tri. In May, the United States launched Linebacker I to interdict enemy lines of communication, which failed to weaken the NVA as it fought through the summer. Instead, in September the ARVN and US air forces combined arms offensive retook Quang Tri. The decisive defeat of the NVA convinced Hanoi to accept a peace treaty. However, South Vietnamese President Nguyen Thieu, excluded from the secret talks, balked at any deal that allowed NVA troops to remain in the country. After the November 1972 election, President Nixon ordered Linebacker II, the bombing of Hanoi, which compelled the North Vietnamese to return to Paris, but only to sign an agreement they had accepted in October following their defeat in the Easter Offensive.