Cycles of war
After the fall of 1965, the war on the ground in South Vietnam fell into a repetitive rhythm of gnawing communist winter-spring offensives, punctuated by major allied search-and-destroy operations. Forces of the Republic of Korea and Australia joined the fight, along with smaller contingents from Thailand and New Zealand.

The U.S. boasted enormous air strength in South Vietnam. By day, the skies were filled with armadas of Army helicopters: UH-1 assault, gunship, and “Dustoff” medical-evacuation helicopters and later specialized UH-1G “Cobra” gunships; OH-23, OH-6, and later OH-58 scout helicopters; and “heavy lift” CH-47 “Chinooks” and CH-54 flying cranes. The Marines operated substantially smaller numbers of UH-1s, H-34s (originally designated HUS) and, later, CH-46s and CH-53s.

Once the initial ship-borne unit deployments were completed, men arrived in and left Southeast Asia mainly aboard U.S. Air Force C-130 and C-141 transports and civilian DC-8s and Boeing 707s under Department of Defense contracts. A constant flow of Air Force transports, mostly C-123s and C-130s, moved men, munitions, and supplies from base to base, with C-130s connecting South Vietnam with Thailand, the Philippines, Taiwan, and Japan. Army C-7 Caribous, transferred to the Air Force, were used to move men and supplies internally in South Vietnam.

Fire support for allied ground forces was provided by Air Force F-100s, A-1s, and F-4s, and Marine F-4s and A-4s. These were directed by an array of airborne Air Force, Army, and Marine FACs (forward air controllers), flying O-1 “Bird Dogs.” The Air Force later deployed O-2 and, following the Marine Corps’ lead, OV-10 FAC aircraft.

The USAF fielded side-firing gunships: The AC-47 “Spooky,” followed in 1972 by the AC-130 “Spectre.” Both were remarkably effective in close support of troops in contact, particularly at night, and both were used for night interdiction of the Ho Chi Minh Trail – in the case of the AC-47 with disastrous results; since it had no means of detecting the fire control radars directing communist anti-aircraft artillery batteries, the Spooky force was decimated. Daylight bombardment of the Ho Chi Minh Trail was conducted by the same units committed to Rolling Thunder, plus South Vietnam-based twin-jet B-57 bombers and, for a time, limited numbers of refurbished piston-engined A-26 light bombers and single-engined AT-28 attack aircraft.

In Laos, anticommunist guerrillas recruited from among the Yao, Man and Hmong hill tribes, Royal Lao Army units, and Thai ground forces (who officially were not there) received limited air support from the tiny Royal Lao Air Force, flying AT-28s, and on occasion from Thailand-based US Air Force units. From 1966, a limited number US Air Force FACs flying O-1 “Bird Dogs” were based in Laos, though their existence was never acknowledged. Anticommunist ground forces in Laos were largely supplied from the air by single-engined UH-10 Helio Courier and Pilatus Porter STOL (short takeoff and landing) aircraft, plus C-123s, C-7s, and antiquated C-47s and C-46s, veterans of operations over “The Hump” in World War II. A small number of ex-Marine H-34s were also used, later replaced by UH-1 “Hueys.” These aircraft were operated by civilian airlines under contract to the Central Intelligence Agency, most notably Air America, but including Continental Air Services and Bird Air.

Going “Up North”
Meanwhile, the air war “Up North” – the term encompassed northern Laos and North Vietnam – reached a level of intensity unmatched in the annals of aerial combat. Thailand-based Air Force F-105s and F-4s joined Navy A-4s, F-8s, F-4s, and A-6s flying off carriers in the Gulf of Tonkin in attacks on Rolling Thunder targets.

The aviators flying in Rolling Thunder considered President Johnson and Secretary McNamara’s targeting policy overcautious and unrealistically incremental, but there was nothing cautious about the communist defenses. Targets were defended by intense anti-aircraft artillery (AAA) concentrations from the start: Soviet-manufactured 37mm, 57mm, and 85mm guns, and, around Hanoi, 130mm batteries, all ringed with 14.5mm and 12.7mm machineguns. To this, in heavily populated areas the North, Vietnamese added small-arms barrages so dense that the lead formed a grayish mist.

Soviet-supplied radar-guided SA-2 surface-to-air missiles (SAMs) joined the fray in April of 1965, and as the campaign wore on the defenses thickened. Finally, the North Vietnamese used MiG-17 and MiG-21 interceptors to perfection, directing them into American formations with ground-based radar. Under attack, Americans crews salvoed their bombs and missed targets, and all too often fell to MiG kills.

The effectiveness of radar-guided MiG intercepts, AAA and SAMs demanded aerial radar countermeasures. First into the breach was a squadron of antiquated Marine EF-10B radar jamming aircraft deployed to Da Nang in mid-April 1965. Next came Thailand-based Air Force EB-66s, ex-Navy carrier-based twin jet bombers converted into electronic-warfare aircraft. To counter the SA-2, the Air Force developed two-seat fighters with electronic warfare officers (EWOs) in the rear seat to direct their pilots in attacks on SAM radars, first F-100s on an experimental basis followed by the F-105G. The Navy used modified A-6s for the same purpose. Air Force EC-121s and EC-135s were used to collect electronic intelligence and provide warning of MiG and SAM engagements.

The air effort was supported by the USAF Air Rescue Service fielding HH-43 “Huskys” for local base rescue in South Vietnam and, for a time, to cover the Ho Chi Minh Trail and northern Laos from bases in Thailand. From the autumn of 1965, rescue coverage “Up North” and along the Ho Chi Minh Trail was provided by long range HH-3E “Jolly Green” helicopters based in Thailand and later also at Da Nang. The Jolly Greens were supported by Air Commando A-1 squadrons dedicated to the combat rescue role as well as by Rescue-equipped HC-54, and later HC-130, airborne coordination aircraft. From 1967, the HH-3s were fitted for air-to-air refueling from HC-130s modified as tankers. Also from 1967, the HH-3s gave way to the larger and more capable HH-53 giving the combat rescue force an impressive capability.
Rolling Thunder
Rolling Thunder reached a crescendo in the fall of 1967 when President Johnson, for once listening to his military advisors, allowed strikes on fuel storage and electrical- power generation targets in the Hanoi-Haiphong area. F-105s dropped the Paul Doumer Bridge across the Red River – the only rail link between Haiphong and China and the south – in August and again in October. Petroleum storage targets were hit hard and Navy A-6s took out the Uong Bi thermal power plant near Hanoi.

British Charge d’Affairs to Hanoi John Colvin later reported that North Vietnam’s war economy was on the verge of collapse, but it was not to be for Johnson once again ordered a bombing pause. In hindsight, this was critical, for the communists were building up their forces in the south to win the war in a single stroke.

Têt
The communist leaders ordered the 1968 Têt Offensive on the basis of two assumptions. First, Hanoi assumed that an all-out attack would unleash a popular uprising. Second, communist leaders believed that the Johnson administration, hard-pressed by an anti-war movement, would remain eager to negotiate its way out of the war so long as they continued to inflict casualties. In this, the communist leadership was half-right: Far from rising up in rebellion, the South Vietnamese remained neutral, and in many cases aided the ARVN and Americans. On the other hand, the Johnson administration was eager to negotiate, a fact that the communist leadership had taken pains to verify in advance.

The offensive ran into difficulties from the start. PLAF assault and sapper teams led the way – North Vietnamese regulars would have been too visible to ARVN and U.S. intelligence – and were slaughtered. Finding communist troops in the open for once, ARVN and American forces wrought havoc. But the communists had achieved surprise, in the massive scale of their attack if not the timing. Westmoreland was initially skeptical of triumphant reports from the field and accompanied his claim of victory with a request for massive reinforcements.

More to the point, Johnson had called Westmoreland home the previous November to issue optimistic predictions. The war, Westmoreland declared, was approaching a turning point; we were on top. Instead, the American public saw television images of Viet Cong bodies in the courtyard of the U.S. Embassy in Saigon and of massive attacks the length and breadth of South Vietnam. This was winning?

In fact, the U.S. and ARVN were winning and winning big, but in the long run, that counted for less than the television images. Embarrassed and uncomprehending, on March 31, Johnson – having been effectively challenged in the New Hampshire Democratic presidential primary by Senator Gene McCarthy – announced that he would not seek a second term and cancelled Rolling Thunder. In Vietnam, communists took heart; in the United States political turmoil ensued and in the end Richard Nixon emerged as President-elect. Click here to go to Part 5.

U.S. Navy (top) and U.S. Army (middle and bottom) photos courtesy Jim Mesko.