In the 1960s and early 1970s, American GIs fought the Vietcong and North Vietnamese in one of the world’s most difficult and diverse environments. Rural South Vietnam was a land of contrasts. It contained mosquito-infested swamps, sand dunes, water-filled paddies, silt-laden rivers, towering mountains, and dense jungles. These environments posed a significant challenge to American tactics and strategy.
Frequently, the countryside conspired to blunt American military power. Rice paddies bogged down tanks and jeeps, sand and mud jammed the delicate M-16 rifle, and triple-canopy jungle deflected iron bombs and napalm. American infantrymen, assigned the grisly task of hunting down and killing the Communist guerrillas, felt the environment’s effects most directly; and many of them came to view the Vietnamese bush as an ancient, implacable foe.
Frederick Downs, who served in Quang Ngai Province in 1967, remembered how the South Vietnamese land- and waterscape affected the troops under his command, “Up ridges, down ridges, over ridges, wading through rocky streams, hacking at jungle growth, breathing in and hopefully breathing out some of the constant bugs that continuously swarmed around our heads, watching our skin as it quickly deteriorated from the numerous bites, scrapes, cuts, tears, thorns, and other abuses of the environment that attempted to beat our bodies into submission.”
Journalist S.L.A. Marshall, who patrolled with troops of the 4th Infantry Division, witnessed the daily physical challenges confronted by American troops in the Central Highlands, “The two companies spent the next four days moving westward without incident. In that time, they covered not more than 5,000 meters, [about three miles] because it was heavy going all the way, through rock-strewn, bush-covered country, where hill followed hill, with few flat spaces in between, a region riven with numerous rock-walled ravines…The land appeared to be untenanted. They saw not one person or human habitation and found not a sign that the enemy had ever been there.”
South Vietnam’s terrain, heavy vegetation, and swarming insects diminished a foot soldier’s strength and cognitive functions, which increased his reaction time and made him more vulnerable to ambush.
The geographical layout of South Vietnam’s rural hamlets made it difficult, and sometimes impossible, to concentrate U.S. forces. Most South Vietnamese hamlets contained a cluster of huts, tightly-woven hedgerows, coconut and banana groves, fences, pig pens, and vegetable gardens – all of which broke-up U.S. infantry formations and made them susceptible to Vietcong attack. Philip Caputo recounted a foot patrol that took his unit into the hamlet of Ha Na, located along the Vu Gia River southwest of Danang. “Charley Company was ordered to search Ha Na…It proved a hellish task because the village was crisscrossed by thorny hedgerows as cruel and unyielding as barbed wire fences…The result was the division of the company into small groups of confused men….” S.L.A. Marshall saw the same thing while with U.S. troops in the village of Tuy An, Binh Dinh Province, “…the hedgerows and houses, and the piecemeal manner of the deployment, were quite disunifying [sic] and practically defied reorganization at the scene. He [the commander] might have reformed on the haystacked field, but so doing would have offered too broad a target to the enemy mortars.”
The vegetation mosaic had the same effect on U.S. troops as terrain. Across rural South Vietnam grew a plant GIs referred to as the “wait-a-minute” vine because it latched on to a soldier’s cotton fatigues, held him in place, and forced him to stop and untether himself. Reporter Joseph L. Galloway encountered this shrub. “We got into a patch of brush and wait-a-minute vines so thick and thorny that every step had to be carved out with machetes. We covered maybe three hundred yards in four hours, forded a fast-running chest-deep mountain stream just as darkness fell, then huddled in our ponchos, wet and freezing, all night long.”
Elephant grass, which can easily grow up to 10 feet in height in the plateau country between Ban Me Thuot and Kontum, presented a number of problems for U.S. troops. At landing zones, tall elephant grass made it difficult for helicopter pilots to see the ground below them. Unsure of how far to descend, pilots either hovered too high off the ground for a safe, injury-free troop insertion or they ended up making a “hard landing” that damaged their machines.
Rather than offer a respite from the sun, elephant grass held the afternoon heat, making a foot patrol through it a hellish, unforgettable ordeal. A walk through elephant grass, at midday, in the dry season, ranked as one of the least enjoyable of many un-enjoyable experiences in Vietnam. Trooper John Ketwig described what it felt like to walk through a patch of high grass, “I soon discovered that the elephant grass hid a tangle of twisted vines, thorns, and razor-sharp leaves. You couldn’t see your feet. You couldn’t tell what you were stepping on, if it was solid or not. The wall of vegetation hid everything. We inched forward.” The grass’s sharp edges also cut the faces, necks, and exposed arms of infantrymen. A trooper with an open wound, however small, had a good chance of developing an infection in Vietnam’s wet, fetid environment.
Before extensive U.S. defoliation operations began in the mid-1960s, trees and brush covered 80 percent of Vietnam. High-stand trees or jungle made-up 49 percent of that vegetation. In the Central Highlands, the jungle impeded cross-country movement, especially if U.S. troops had to cut their own trail. In mid-1965, a Marine foot patrol through the Tuy Loan Valley took four hours to cover three miles. The jungle, the heat, and the constant threat of ambush frequently slowed American foot patrols to a snail’s pace.
U.S. troops often became disoriented in the midst of the jungle. The wall of green on all sides reduced visibility so much that American GIs could not always locate and identify landmarks or verify their position on a map. A unit that became lost had a greater chance of falling victim to a Vietcong attack or being accidentally hit by U.S. artillery and air strikes.
In the deepest jungle, visibility dropped to a few feet, even during daylight hours. In those moments, and in those hidden places, American soldiers walked blindly through a perilous land. Trooper Jerry Johnson remembered the time his unit stumbled upon a Communist base camp, “…We had walked through triple-canopy jungle right into an enemy bunker complex. It was so thick you could walk right up on a bunker and not see it.”
On moonless nights, an absolute darkness descended upon the jungle. All shape, shadow, and hint of light disappeared beneath a black veil. Only the unnerving, primordial sounds of the forest let a man know he hadn’t sunk into an abyss. S.L.A. Marshall recalled a night in the jungle. “At the position on top of the mountain fog settled in several hours before midnight. Combined with the steady drizzle, it cut visibility to a few feet, though that made little difference. The tangled growth all about them was so dense that each man could feel of the company presence only the two or three soldiers lying closest to him.”
Dawn did not always improve visibility; as one GI noted, “At three-thirty in the morning the top of the jungle is just becoming visible. The skies are lightening, but the ground mists, heavy and sullen, snuff out what little light there is, making it almost impossible to see even a few meters.” In the murky, timbered reaches of the Central Highlands, the Vietcong sprung attacks on American troops from only a few feet away.
American helicopter pilots had a hard time safely landing their damaged choppers in contiguous stands of timber. The odds of surviving a helicopter crash in thick jungle were low. Doomed choppers first slammed into the treetops and then tumbled toward the earth, their whirling blades violently slashing a jagged path through branches and vines. If a crew didn’t die on impact in the upper canopy, they perished as the helicopter broke apart on its way to the ground. Pilot Tom A. Johnson considered helicopter operations over thick jungle to be particularly dangerous. Flying near Khe Sanh, he observed, “The land below us is strange. None of us has ever flown in this territory, so each mile is a new adventure. Mountains bolt out of small lush green valleys. I have yet to see a single flat or jungle-free space since we took off. Engine failure here means serious trouble. Helicopters and their crews have disappeared into jungle like this and never been seen again.”
The jungle negated U.S. firepower too. The tallest jungle trees grew to a height of 200 feet or more. These giants loomed over the forest floor, their branches and leaves casting long shadows across the ground. Big trees, including hopea odorata and tetrameles nudiflora, provided a natural umbrella to the Vietcong under their protective cover. Time and again, U.S. iron bombs, artillery shells, rockets, cluster bombs, and mortar rounds detonated in the jungle’s upper canopy. Branches and tree trunks at lower levels absorbed flying shrapnel and deflected the concussive force of the blasts. S.L.A. Marshall became highly critical of the use of artillery in thick jungle, he wrote, “A 105-mm. howitzer, firing at a jungle mass, is somewhat deadlier than a pea-shooter, though not much.”
The jungle also lessened the fatal reach of napalm. U.S. aircraft, including the A-1H Skyraider, F-4 Phantom, and F-100 Super Sabre, dropped the jellied gasoline on Vietcong and North Vietnamese troop columns, bunker complexes, trench lines, and base areas. It fell from the sky in silver, cigar-shaped canisters. The Americans designed the canisters to tumble through the air end over end to ensure that at the moment of impact the released napalm spread as far afield as possible. In open country, napalm killed with a gruesome efficiency. But in triple-canopy jungle it was far less effective. Often, the canisters broke open high up in the trees, sending sizzling jello through the upper and middle story, rather than across the heads, shoulders, and backs of the Communist infantrymen at ground level.
The jungle also limited the effectiveness of the M-16 rifle. Infantryman Charles Albridge thought the M-16 unsuitable for the war in Vietnam. “Initially, the men liked it [the M-16]. They went from a rifle that weighed 9 pounds to one that weighed just over 5,” said Albridge, “…any time you give a soldier less weight to carry, he’s happy. About the time they realized that a twig would deflect the bullet and 30 percent of your rounds fired into a jungle never got past the underbrush, you started mistrusting the weapon.”
For the Vietcong and North Vietnamese, the jungle acted as a giant shock absorber by dissipating the killing power of American artillery, napalm, and rifle fire.
Dust and sand particles presented American troops with another set of problems. Sand gummed up every manner of machine, battered helicopter rotor blades, and jammed the fickle M-16. Sand wore down the brake pads and drums in the Army’s four-wheeled vehicles, requiring replacement of those parts far sooner than otherwise would have been the case. During the dry season, sand and dust became particularly troublesome on the large U.S. bases built atop the sand expanses at Cam Ranh Bay, Qui Nhon, Tuy Hoa, Dong Tam, and Chu Lai. By late 1967, South Vietnam had lost millions of acres of plant cover to defoliation, aerial bombardment, and ground combat operations. All across the country, barren dirt patches replaced greenery. Clear fields of fire and vegetation-free roadsides enhanced the security of U.S. forces, but the tons of airborne grit resulting from U.S. military activities reduced operational readiness.
The difficulty of conducting military operations in rural South Vietnam convinced American GIs that the land itself represented a malevolent force. No other region conjured up the idea of Vietnam as a hostile land more than the Central Highlands, an area known to the Vietnamese as the Truong Son. Aware that the Vietcong and North Vietnamese wandered across the hills and through the valleys of the Truong Son, usually at night or under the cover of clouds, rain, and fog, only added to the sense of foreboding GIs felt for the place. In the highlands, a man’s imagination ran wild and nightmares came true.
Marine Lieutenant Philip Caputo saw the highlands for the first time from a helicopter. “We were flying parallel to the mountains; the Cordillera spread out before us, and it was the most forbidding thing I had ever seen. An unbroken mass of green stretched westward, on ridgeline and mountain range after another, some more than a mile high and covered with forests that looked solid enough to walk on. It had no end. It just went on to the horizon. I could see neither villages, nor fields, roads, or anything but endless rain forests the color of old moss. There it was, the Annamese Cordillera, hostile and utterly alien.”
The highlands also deeply impressed reporter Michael Herr. He wrote, “…The Puritan belief that Satan dwelt in Nature could have been born here, where even on the coldest, freshest mountaintops you could smell jungle and that tension between rot and genesis that all jungles give off. It is ghost-story country.”
With the natural environment conspiring against them and with the Communists using that environment to their advantage, GIs came to perceive rural South Vietnam as inimical to their presence. And because they knew the Vietcong maintained an intimate connection to the land, the Americans did not make any distinction between the land and the Communist enemy. Both the Vietcong and Vietnam were hell-bent on killing GIs. But the Americans were not helpless; they had powerful weapons of their own to counter the Vietcong’s land-based advantages. They could direct artillery, jet fighters, B-52 bombers, helicopter gunships, U.S. Navy destroyers and the world’s largest battleships against the Vietcong and their land. Viewing the land as one with the enemy, the Americans blew the land apart.
 Frederick Downs, The Killing Zone: My Life in the Vietnam War, (New York: W.W. Norton & Company, 2007), 110.
 S.L.A. Marshall, West to Cambodia: Fierce Fights to Block Enemy Infiltration into Vietnam, (New York: Cowles Education Corporation, 1968), 32.
 S.L.A. Marshall, The Fields of Bamboo: Dong Tre, Trung Luong and Hoa Hoi, Three Battles Just Beyond the South China Sea, (New York: The Dial Press, 1971), 88.
 Philip Caputo, A Rumor of War, (New York: Henry Holt and Company, Owl Books, 1996), 299.
 Marshall, Fields of Bamboo, 88.
 Harold G. Moore and Joseph L. Galloway, We Were Soldiers Once…And Young, Ia Drang: The Battle That Changed the War in Vietnam, (New York: Random House, 1992), 32.
 Ibid., 65.
 Ronald J. Glasser, 365 Days, (New York: George Braziller, Inc., 1971), 94; John Ketwig, and a Hard Rain Fell: A GI’s True Story of the War in Vietnam, (Naperville, Illinois: Sourcebooks, Inc., 2002), 155.
 Bernard B. Fall, The Two Vietnams: A Political and Military Analysis, (New York: Frederick A. Praeger, 1963), 3.
 Caputo, Rumor of War, 87.
 Marshall, West to Cambodia, 194.
 Downs, The Killing Zone, 92.
 Christian G. Appy, Patriots: The Vietnam War Remembered from All Sides. (New York: Viking, 2003), 138.
 James R. Ebert, A Life in a Year: The American Infantryman in Vietnam, 1965-1972, (New York: Presidio Press, Ballantine Books, 2004), 168-169.
 S.L.A. Marshall, Battles in the Monsoon: Campaigning in the Central Highlands, South Vietnam, Summer, 1966, (Nashville: The Battery Press, Inc., 1966, 1967), 36-37.
 Glasser, 365 Days, 108.
 S.L.A. Marshall, Bird: A Christmastide Battle., 1968, Reprint, (Nashville, Tennessee: The Battery Press, 1983), 156; Marshall, Battles in the Monsoon, 161.
 Tom A. Johnson, To the Limit: An Air Cav Huey Pilot in Vietnam, (New York: New American Library Caliber, 2007), 66, 99, 100.
 Ibid., 269.
 Marshall, Battles in the Monsoon, 36-37, 49; John Schlight, The War in South Vietnam, The Years of the Offensive, 1965-1968, The United States Air Force in Southeast Asia, (Washington, D.C.: Air Force History and Museums Program, 1999), 231, 276.
 Marshall, West to Cambodia, 119; Keith W. Nolan, Into Laos: The Story of Dewey Canyon II/Lam Son 719, Vietnam, 1971, (Novato, California: Presidio Press, 2000), 173.
 Schlight, War in South Vietnam, 182, 274.
 Eric M. Bergerud, Red Thunder, Tropic Lightning: The World of a Combat Division in Vietnam, (New York: Penguin Books, 1994), 50; Shelby L. Stanton, The Rise and Fall of an American Army: U.S. Ground Forces in Vietnam, 1965-1973, (Novato, California: Presidio Press, 1985), 173.
 Schlight, War in South Vietnam, 171.
 Ebert, A Life in a Year, 126.
 Caputo, Rumor of War, 82.
 Michael Herr, Dispatches, 1977, Reprint, (New York: Vintage Books, 1991), 94.