World: HOW THE BATTLE FOR KHE SANH WAS WON

As allied patrols scoured the scorched and battered moonscape around the liberated Marine garrison of Khe Sanh last week, they found North Vietnamese trenches and bunkers, tons of supplies and ammunition, some 1,300 bodies—and hardly a trace of opposition. Whether fled or dead, the formidable force of 20,000 North Vietnamese assault troops that had ringed 6,000 U.S. Marines and ARVN troops was gone. What once loomed as the largest, most decisive and most controversial battle of the Viet Nam war would now never be joined, and the forebodings of the armchair generals* who questioned the decision to defend Khe Sanh had proved unfounded.

But a major battle did occur at Khe Sanh—one that prevented the bloody hand-to-hand battle on the ground that many military men had anticipated. It was a battle of the air might of the U.S. against every stratagem that the besieging enemy could muster. Bombing the North Vietnamese with such precision that they were destroyed before they could ever launch their attack, the U.S. could justly claim a considerable victory at Khe Sanh without ever having committed its ground forces to the fray. Khe Sanh was, in fact, a landmark in the use of airpower in warfare—the first time that aerial bombardment has denied an attacker the ability to assault his target.

From the beginning of the North Vietnamese buildup around the Marine base, the U.S. command was convinced that North Viet Nam’s Defense Minister, General Vo Nguyen Giap, intended to try to overrun Khe Sanh as he had stormed Dienbienphu 14 years earlier. As he had done against the French garrison, Giap assembled large numbers of his best-trained assault troops around Khe Sanh, together with huge quantities of weaponry.

In addition, deep in the Laotian hillsides Giap placed Russian-made 152-mm. cannons, their long tubes zeroed in on besieged Marines. Altogether, Hanoi’s gunners poured more explosives into Khe Sanh than they had into Dienbienphu, reaching a peak on Feb. 23, when 1,300 rounds slammed into the U.S. base. And, as in 1954, the North Vietnamese by night tunneled ever closer to the Marine perimeter, drawing the net of fortified attack positions ever tighter. In terms of firepower and supplies, the Communists were better prepared to strike at Khe Sanh than they ever had been at Dienbienphu. During the early days of the six-week siege, they even had the weather—low clouds, fog and mist—in their favor.

Looking at the situation, the U.S. decided that the only way to defend Khe Sanh was by a massive application of airpower. At Tan Son Nhut airport outside Saigon, General William W. (“Spike”) Momyer set up a special command whose sole mission was to orchestrate an aerial operation around Khe Sanh. Working over a sandbox model of the Khe Sanh area, two of the U.S. Army’s most gifted tacticians—General Creighton Abrams and Lieut. General William B. Rosson—figured out the most logical places for Giap to concentrate men and supplies, then designated those areas as prime targets for U.S. planes. Dozens of reconnaissance aircraft were sent out to crisscross the area around Khe Sanh; even the heat from a match was enough to warn their sensitive infra-red cameras of Communist presence below.

Working on a round-the-clock basis, photo-intelligence analysts studied the pictures and selected promising targets. In addition, pilots in tiny FAC planes hovered continually over the battlefield to locate the more easily indentifiable targets. To coordinate all the activities, an ABCCC (Airborne Command and Control Center) was kept in the sky high over Khe Sanh at all times. It was a C-130 Herky Bird packed with the latest electronic gear, which enabled the Air Force colonel on board to talk with Marines on the ground, pilots in the surrounding sky and his own superiors in Saigon.

U.S. airmen enclosed the besieged fortress in a virtual curtain of falling bombs. Though the Marines lost most of their original supply of artillery ammunition when an enemy shell hit their supply dump early in the siege, they were able to call in airpower for the sort of pinpoint destruction that is normally associated with howitzers. When the lowering clouds lifted a few hundred feet, dartlike Air Force F-100s, Navy and Marine F-4 fighter-bombers and stubby A-4 light bombers zipped under the overcast to place high explosives on the spreading enemy trenches. Huge, eight-jet B-52s, which bomb by radar, flew over Khe Sanh regardless of the weather.

At first, Khe Sanh’s barren landscape presented problems for the B-52s’ radar system, which usually takes a fix on a prominent ground feature, such as a bridge or high building. To solve that, the U.S. employed a recently developed system called “Sky Spot.” Using a power ground-control center on South Viet Nam’s coast, Sky Spot directed the bombers to the general area of their destination. There, on hilltops miles from the fighting, the U.S. placed meshes of wire that acted as radar reflectors and electronic beacons that emitted continuous signals. Gauging the distance to their targets from these spots, the B-52s were able to bomb with uncanny accuracy; the big bombers, in fact, were able to walk their sticks of bombs to within 100 yds. of the perimeter of the Marine bastion. Flying the 5,200 mile round trip from their Guam base, they averaged 40 to 50 strikes each day. Hardly an hour passed without a bombload falling on the Communists. In ten weeks, a total of 103,500 tons of explosives were dumped on the five-mile-square battlefield around the base.

The bombing struck dread into the North Vietnamese. They feared the fighter-bombers, but most of all they feared the B-52s. Reason: the B-52s fly so high—above 40,000 ft.—that their approach is unknown to those on the ground until the huge bombs fall on them. According to the U.S. estimates, 15,000 enemy troops were killed or injured by U.S. bombardment. The bombs obliterated trenches, leveled hills, scorched whole acres of land. They even wiped out the North Vietnamese headquarters bunker, killing all those inside. The bombing touched off 5,000 secondary explosions and more than 2,000 fires in the immediate vicinity of Khe Sanh, indicating that ammunition and gasoline caches were being hit hard. In all, the Air Force estimates that the bombing destroyed 3,500 tons of Giap’s supplies—enough to sustain a full division in combat for a month.

Some time around March 12, the day before the 14th anniversary of his victory at Dienbienphu, General Giap seems to have come to the conclusion that he would not be able to repeat his earlier feat, and he stopped sending replacements to Khe Sanh. Then, on March 22, he ordered one of his two battered divisions around Khe Sanh to withdraw. That same day the monsoon began to lift from Khe Sanh, and the better weather brought the fighter-bombers to join with the B-52s in earth-jarring raids. The heavy U.S. bombing only heightened the desire of the remaining North Vietnamese troops to get out. The testimony of captured NVA regulars indicates that the bombing so disrupted the Communist supply lines that Giap’s men were nearly starving.

The prisoners said that they had been subsisting for weeks on less than half a pound of rice a day; for the last three days before their capture, they had had no food whatsoever. Relieved to be free of the threat of instant death, the prisoners told of one regiment that had lost 75% of its 2,000 men to U.S. bombs and artillery.

The evidence on the battlefield was even more persuasive testimony of the extent of the U.S. victory. The North Vietnamese are normally an extremely frugal foe that never leaves even a rifle bullet behind. In their haste to get away from Khe Sanh, they left piles of valuable matériel. In only a cursory search of the area, U.S. troopers counted 182 rockets and mortars, 260,000 rounds of small-arms ammunition, 13,000 rounds of larger-caliber ammunition and 8,700 hand grenades and mines. Several hundred North Vietnamese even left behind their AK-47 rifles, violating the most basic principle of war—that an infantryman never loses his weapon even in retreat. The idea that the North Vietnamese pulled out as a voluntary gesture of de-escalation is thus contradicted by all the facts. The biggest fact is that at Khe Sanh they were badly whipped by U.S. airpower.

*Among them: Historian Arthur Schlesinger Jr., who, in a letter to the Washington Post on March 22, asked for a pullout: “Khe Sanh has lost whatever military significance it may have had. It is highly vulnerable. Airpower will not save it. Let us not sacrifice our brave men to the folly of generals and the obstinacy of Presidents.”