For the Common Defense

by Allan R. Millett, Peter Maslowski

  Johnson chose a gradual squeeze and nursed ROLLING THUNDER through three overlapping phases. Initially, interdiction dominated. Even the JCS, disappointed at Johnson’s “slow squeeze” strategy, believed that attacking lines of communication would demonstrate American resolve and diminish the North’s support for the VC. But North Vietnam mobilized civilian repair crews to rebuild roads and bridges, built redundancy into the transportation network, and appealed to China and the Soviet Union for more support. When trucks were too few or too vulnerable, the enemy used porters or bicycles designed to carry up to 500 pounds. Moreover, enemy forces in the South needed little external support. The VC grew much of their food, produced medicine from local plants, captured weapons and ammunition from ARVN, and bought supplies on South Vietnam’s thriving black market. Those PAVN forces inside South Vietnam were light infantry with no tanks, planes, and heavy artillery requiring a complex logistical system. Total daily requirements for enemy forces in the South totaled 380 tons, of which only thirty-four tons per day came from outside sources. Seven two-and-a-half-ton trucks could fill this need. No amount of bombing could stem the trickle of supplies that needed to reach the South.

  In late 1965 the JCS, despite skepticism from other agencies, determined that oil was essential to the North’s infiltration capability. The next spring Johnson permitted the bombing to shift from interdiction to oil, beginning with attacks on small storage facilities in unpopulated areas. Then in late June bombs struck large POL (petroleum, oil, and lubricants) facilities in Hanoi and Haiphong, which had previously been off limits. The oil campaign seemed a great success: Warplanes destroyed 80 percent of the North’s bulk fuel capacity. It made no difference. Never needing much fuel, North Vietnam now received more POL supplies from China and the Soviet Union, and dispersed 55-gallon fuel drums along transportation routes and in small underground storage sites. In the Jason Summer Study, a group of leading scientists examined data the administration provided and concluded that “North Vietnam has basically a subsistence agricultural economy that presents a difficult and unrewarding target system for air attack.”

  The oil campaign’s failure, with the glaring discrepancy between the military’s optimistic prestrike predictions and the pessimistic poststrike reality, convinced McNamara to search for a better option that would impair Hanoi’s ability to continue supporting the war in the South. He settled upon a proposal recommended by a special study group that called for a network of manned and electronic obstacles stretching from the South China Sea across Vietnam just below the DMZ and continuing into the Laotian panhandle. Carefully positioned technical devices (such as seismic and acoustic sensors), weapons, and manned positions might substantially reduce the flow of men and supplies. Although neither MACV nor the JCS was enthusiastic about the project, in January 1967 President Johnson not only approved it but also assigned it the highest national priority. The so-called McNamara Line ran into difficulties from the start. PAVN operations disrupted construction, Laos rejected the idea of a cross-border barrier, and Westmoreland insisted that it drained manpower that could be better used in search-and-destroy missions. Still, air-delivered seismic intrusion detectors (ADSIDs) helped to pinpoint trucks moving down the Ho Chi Minh Trail, allowing U.S. warplanes to destroy a substantial number of them, and undoubtedly killing a large number of PAVN soldiers as well.

  But if McNamara had lost faith in the air war against North Vietnam, the same was not true for the air chiefs. Having only marginally influenced the war by interdiction and attacking oil, they asserted that the North’s real Achilles’ heel was industry and electric power. Although some advisers warned Johnson that North Vietnam contained no worthy industrial target system, in the fall of 1966 he sanctioned raids on the North’s only steel factory, its sole cement plant, and all its thermal power plants, though the largest of these only produced the kilowatts necessary for an American town of 25,000. Soon 87 percent of North Vietnam’s electric-generating capacity and its few industries were in ruins, but the North compensated with thousands of generators and additional Chinese and Soviet aid. Another Jason Summer Study discovered that the bombing “had no measurable effect on Hanoi’s ability to mount and support military operations in the South.”

  ROLLING THUNDER increasingly resembled Stephen Crane’s “single, long explosion” with broader geographic scope, more sorties (the number increased fourfold between 1965 and 1968), more bombs, and expanded target lists. But political, military, and operational constraints prevented it from ever becoming the unrestricted effort the JCS advocated. Political constraints flowed from Johnson’s “negative objectives”—that is, things he did not want to happen. While pursuing his positive objective of an independent, non-Communist South Vietnam, the president wanted to avoid alienating NATO allies, undermining his “Great Society” domestic social reform programs by diverting attention and money from them, or, most important, provoking large-scale Chinese or Soviet participation in the war. Paradoxically, to save ARVN the U.S. had to apply force, but to avoid a wider war it had to limit the force it applied. For the Vietnamese, of course, it was always a war without limits.

  No one knew what the Chinese or Soviet threshold was for entering the war. Along with economic aid and military equipment, China sent 320,000 troops to North Vietnam between 1965 and 1969, primarily engineering units and antiaircraft troops. North Vietnam received assurances that if the Americans invaded, China would intervene, and the Communists made sure the U.S. knew of these assurances. As for the Soviets, they provided the North everything from medical supplies to jet fighters and by 1969 eclipsed China as Hanoi’s primary benefactor. The Kremlin also sent 3,000 “advisers,” some of whom manned antiaircraft defenses. And the U.S.S.R. threatened to send “volunteers” to the North.

  At one point Johnson asked JCS Chairman Earle Wheeler and MACV Commander Westmoreland at what point the Chinese or Soviets might intervene. “That,” responded the latter, “is a good question.” Indeed it was, and the president could ill afford to ignore it. Because the enemy had two “big brothers that have more weight and people than I have,” he hedged the bombing with restraints, which loosened as the war continued but never disappeared. He specified strike days, selected targets, limited the number of sorties, and for most of ROLLING THUNDER forbade attacks within thirty nautical miles of Hanoi and ten miles of Haiphong, and in a twenty-five-mile-wide buffer zone along the Chinese border. Deciding whether to hit a target, said McNamara, required balancing the target’s value, the risk of pilot loss, and the possibility of widening the war. Some targets were so insignificant they were not worth the risk of lost planes and airmen; others, political leaders feared, might ignite World War III.

  Another political restraint consisted of eight bombing halts, most of them only a few days but with one lasting more than a month. Because North Vietnam insisted it would not negotiate while being bombed, the administration confronted pressure to stop the bombing as a diplomatic signal that the U.S. was willing—even eager—to negotiate. The armed forces predicted—correctly—that the enemy would use these lulls, not to negotiate, but to rebuild defenses, repair damage, and hasten men and material southward.

  Three military constraints limited ROLLING THUNDER. Initially, airfield construction was so slow it delayed the buildup. Even as planes arrived, they confronted a munitions shortage because the production of 500- and 750-pound bombs was insufficient until the spring of 1967. A tangled command system also hindered ROLLING THUNDER since, in a violation of the concept of unity of command, no single commander controlled theater air operations. BARREL ROLL and STEEL TIGER remained divided from ROLLING THUNDER, and the air war inside South Vietnam was another separate enterprise. In the skies over North Vietnam, “order” emerged in April 1966 when CINCPAC Admiral Ulysses S. Grant Sharp divided the target area outside South Vietnam into seven “Route Packages.” General Westmoreland scheduled strikes in Route Package I, which lay immediately north of the 17th Parallel. The other six were under Shar
p’s command, with Route Packages II, III, IV, and VI B (including Haiphong) allotted to the Navy, and Route Packages V and VI A (including Hanoi) to the Air Force. No matter where B-52s flew, they remained SAC’s responsibility. The most significant military restraint was a bombing doctrine that emphasized destroying an enemy’s capability to fight by ruining its vital centers. The air chiefs devised plans to wreck the North’s economy by attacking the transportation system, oil, its few factories, and electric power. But with a rudimentary transportation system and tiny industrial base, North Vietnam was not a vulnerable target for a sustained air campaign with urban-industrial targets.

  Operational controls such as the weather and enemy defenses also imposed limitations. From May through August the skies were relatively cloud-free. For the rest of the year weather conditions made daylight bombing difficult, and at night planes had to use flares to see a target. Pilots found their targets less than one-third of the time. Among the bomb-carrying planes—F-105 Thunderchiefs (called “Thuds”), F-4 Phantoms, A-4 Skyhawks, and A-6 Intruders—only the Navy’s Intruders had an all-weather capability, but usually no more than two squadrons (thirty-two planes) were available. North Vietnam responded by mobilizing repair crews, evacuating the cities, and adjusting work schedules to reduce vulnerability—which was fairly easy, since bombing raids followed predictable routines, and strike packages were big, obvious, and often compromised in advance by enemy spies and signals intelligence. As for active defenses, with Soviet and Chinese assistance, the North built a formidable, layered air-defense system integrating radar, antiaircraft artillery, surface-to-air missiles (SAMs), and MiG fighters.

  Before ROLLING THUNDER ended on October 31, 1968, the U.S. had dropped 634,000 tons of bombs (approximately 100,000 tons more than it dropped in the Pacific theater in World War II), doing $600 million in damage and killing 52,000 civilians out of a population of 18 million. Although the enemy claimed it shot down more than 3,000 planes, the U.S. lost “only” 938 (hundreds of others suffered damage), costing about $6 billion. In warplane losses alone it cost $10 to inflict $1 worth of damage. And between 1965 and 1968 North Vietnam received more than $2 billion in foreign aid, more than compensating for its losses.

  In any event President Johnson never believed the U.S. could win the war by bombing the North. Indeed, he often privately expressed ambivalence about the entire war. “I don’t think anything is going to be as bad as losing,” he told McNamara in January 1965, “and I don’t see any way of winning.” Nonetheless, he plunged ahead.

  Entering the Ground War

  Shortly after authorizing ROLLING THUNDER, the president initiated an American ground war inside South Vietnam in addition to an enormous air war. The buildup began when two Marine battalions arrived at Da Nang to guard the air base there; and by June 1, 1965, the ground forces approved for Vietnam numbered 77,250. Painting a bleak picture of ARVN, Westmoreland asked for reinforcements to provide “a substantial and hard-hitting offensive capability on the ground to convince the VC that they cannot win.” Johnson asked his military advisers whether the enemy could match an American buildup. The “weight of judgment,” Chairman Wheeler responded, was that the enemy could not. The president also consulted the “Wise Men,” a bipartisan group of elder statesmen who seconded the military in recommending an expanded war. And McNamara believed the only options were to withdraw and be humiliated, continue the same failed strategy, or expand the effort, with the latter option presenting “the best odds of the best outcome with the most acceptable cost to the United States.” Dissenting voices were few, with Under Secretary of State George Ball being a notable exception. He predicted that approving Westmoreland’s request would result in “a protracted war involving an open-ended commitment of U.S. forces, mounting U.S. casualties, and no assurance of a satisfactory solution, and a serious danger of escalation [involving the Chinese or Soviets] at the end of the road.”

  Johnson chose a bigger war. In late July he authorized 50,000 more men immediately, another 50,000 by year’s end, and, implicitly, still more troops if Westmoreland needed them. Thus began the gradual increase in American military personnel inside South Vietnam that peaked at 543,400 in early 1969. By ratcheting up the war’s scale and intensity, both in the skies over North Vietnam and especially inside South Vietnam, Johnson hoped to find Hanoi’s breaking point. When the destruction reached the right intensity, he believed the enemy would negotiate on U.S. terms to avoid greater suffering.

  “This is no longer South Vietnam’s war,” a White House aide wrote in a memo capturing the significance of Johnson’s decision. “We are no longer advisers. The stakes are no longer South Vietnam’s. We are participants. The stakes are ours—and the West’s.” The Communists also recognized how crucial Johnson’s decision was. In their parlance, it marked the failure of America’s “special war.” But rather than negotiate, as Hanoi had hoped, the U.S. was escalating to what North Vietnamese strategists labeled a “limited war,” sending its own forces to rescue a disintegrating ARVN. The North’s gamble that it could defeat Saigon without provoking the U.S. to increase its involvement had failed. America’s escalation compelled the Communists to undertake a strategic reevaluation. During centuries of intermittent warfare the Vietnamese had expelled the Chinese, thrice repelled Kublai Khan’s Mongols, and then whipped France. Now confronting another powerful adversary, they sought to defeat it through revolutionary (or people’s) war, which was neither guerrilla warfare nor conventional warfare, though it incorporated features of both. The Vietnamese embraced a “war of interlocking” in which “the regular army, militia, and guerrilla forces combine and fight together.”

  At the apex of the enemy’s military structure was PAVN, a conventionally organized army that grew to eighteen infantry divisions and twenty independent regiments, plus armored and artillery regiments. The VC’s Main Forces, organized into battalions, regiments, and even divisions, were akin to PAVN regulars, while their Local Forces consisted of companies that operated at the province level. Beneath the Main and Local forces was the “militia,” which incorporated part-time guerrillas; self-defense forces that included older people, women, and youths; and secret self-defense forces that were identical to self-defense forces except they lived in hamlets controlled by South Vietnam. The Viet Cong Infrastructure (VCI) was responsible for gathering intelligence, collecting taxes, recruiting, and conducting sabotage and assassinations. Although the U.S. military considered regular forces distinct from irregulars, Communists perceived them as complementary, like yin and yang, a union of opposites with a synergistic effect that made their combined power greater than either of them alone.

  The Vietnamese made no distinction between political and military struggle (dau tranh); the relationship between the two struggles was symbiotic, with political dau tranh being the anvil and military dau tranh the hammer. Their interweaving of political and military dau tranh and their willingness to forego tidy strategic formulas fascinated one American general who observed that the VC/NVA conducted “a different kind of war” in each province. One might be relatively peaceful as the enemy stressed political dau tranh, while simultaneously conventional warfare convulsed a neighboring province and guerrilla conflict simmered in another. To the Vietnamese no distinction existed between civilians and combatants, so they enlisted not just battle-age men but women, children, and old folks. One study concluded that women commanded 40 percent of all PLAF regiments, while children served as lookouts, built booby traps, and flung grenades.

  Ho and his followers understood that a protracted war might be necessary: Nurturing political support took time, and a powerful adversary was not quickly defeated. But they reasoned that time was on their side since the U.S. had no compelling national interest to fight in Vietnam, while they did. Their goal was to deflate America’s “aggressive will,” to win a political and psychological victory that made the U.S. unwilling to continue fighting. Avoid losing long enough and inflict a drip, drip, drip of casualties,
and over time the U.S. would accept defeat.

  As a result of their strategic debate the Communists decided to match the U.S. escalation, with the objective of bogging their foes down in a protracted struggle and creating a stalemate that sapped American (and South Vietnamese) morale. Hanoi directed much of its effort to convincing the U.S. that its “limited war” had failed. For the U.S. to win it would have to escalate dramatically, possibly igniting a “general war” involving the Chinese or Soviets. When confronted with a choice between “general war” or de-escalation, most enemy strategists presumed America would choose the latter.

  While the adversary wrestled with its strategic options, and with reinforcements on the way, Westmoreland formalized a “Concept of Operations” outlining a three-phase victory plan. Initially the U.S. and its allies would halt the losing trend by year’s end. During Phase Two, spanning the first half of 1966, they would assume the offensive, destroying enemy units in high-priority areas. Phase Three entailed the enemy’s nearly complete destruction by the end of 1967, thus allowing U.S. troops to begin withdrawing. As so often happened, a seemingly good plan did not withstand the test of combat.

  Westmoreland’s troop buildup went slowly, with one hindrance being logistical support. Problems began in the U.S., where the production base operated at a low level in 1965. As the war geared up, production lagged behind demand, partly because most strategists assumed the war would be over no later than 1967; due to the lead times involved, many manufacturers feared production would peak just as the war wound down. For some specialized items only a single source existed, and often it could not increase production fast enough to meet requirements. Labor strikes in 1967 at key industries further delayed production, and many industries considered consumer goods more profitable than supplying the military. Critical items such as M-16A1 rifles and M-107 self-propelled gun tubes always remained in short supply.