Joint warfare in South Vietnam 1964-1968

A new situation arose due to the overthrow of Diem, the two coups shortly following, the Gulf of Tonkin incident, and increasing intensity in the war.

Note that Minh was exiled within the same month as the Gulf of Tonkin incident, with its obvious ramifications of increased U.S. involvement.

1964

September 1964: SVN explores governments

Under Khanh, the start of a civilian government, called the High Legislative Council, started in September, with Pham Khac Suu as head of state and Tran Van Huong as Premier and head of government. INR, however, did not believe this council would gain traction unless it was perceived as representative by both the populace and the military. Khanh dissolved the council in December, in the face of new demonstrations, although he temporarily retain Suu and Huong, dismissing them in December. Khanh, according to INR, created a new tension with the Buddhists that Huong had not, and also may have been approaching Hanoi much as he had accused Minh.

1965

February 1965: new government in Saigon; U.S. intensifies air operations

A coup against Khanh failed in early February, but he left the country within a few weeks, with the Armed Forces Council back in charge. Just before Khanh left, the Council did set up a new civilian government headed by Phan Huy Quat. INR saw the Quat government as evidence of a temporary stability between the military and the Buddhist, but one that could be broken by a power play of factions on either side.

Under Khanh, the start of a civilian government, called the High Legislative Council, started in September, with Pham Khac Suu as head of state and Tran Van Huong as Premier and head of government. INR, however, did not believe this council would gain traction unless it was perceived as representative by both the populace and the military. Khanh dissolved the council in December, in the face of new demonstrations, although he temporarily retain Suu and Huong, dismissing them in December. Khanh, according to INR, created a new tension with the Buddhists that Huong had not, and also may have been approaching Hanoi much as he had accused Minh.

A coup against Khanh failed in early February, but he left the country within a few weeks, with the Armed Forces Council back in charge. Just before Khanh left, the Council did set up a new civilian government headed by Phan Huy Quat. INR saw the Quat government as evidence of a temporary stability between the military and the Buddhist, but one that could be broken by a power play of factions on either side.

On February 6, the VC attacked U.S. facilties at Pleiku, killing 8 and destroying 10 aircraft. President Johnson, on February 7-8, responded with the first specifically retaliatory air raid, Operation FLAMING DART (or, more specifically, FLAMING DART I), of the broader Operation ROLLING THUNDER plan, which had not yet officially started. He made no public announcements, although the U.S. press reported it. The attack was carried out by U.S. Navy aviators from an aircraft carrier in the South China Sea. FLAMING DART II was a response to an attack on Qui Nhon on March 10. In response, initially unknown to the U.S., the North Vietnamese received their first S-75 Dvina (NATO reporting name SA-2 GUIDELINE) surface-to-air missiles, starting an upward spiral of air attack and air defense.

ROLLING THUNDER buildup, March

He approved the sustained Operation ROLLING THUNDER plan on March 13.

On March 8, in response to Westmoreland's request of February 22 reflecting a concern with VC forces massing near the Marine air base at Da Nang, 3500 Marine ground troops arrived, the first U.S. large ground combat unit in Vietnam. In April, he authorized the deployment of an additioal two Marine battalions and up to 20,000 support personnel. Again without public announcement, he changed the rules of engagement to permit the Marines to go beyond static defense, and to start offensive sweeps to find and engage enemy forces.

Carrot and Stick, April

Johnson's main public announcement at the time, however, was an April 7 speech, in which he offered economic support to North Vietnam, and Southeast Asia in general, if it would stop military action. This offer was quite in keeping with his goals for development, the Great Society, in the United States, and was likely a sincere offer. That he saw such an offer as attractive to the enemy, however, is an indication of his lack of understanding of the opposing ideology.

More elaboration of the proposal was in National Security Action Memorandum 329 This initially classified (but at the lowest level) document, among other things, asked for specific recommendations of a "reviews of the pros and cons" of increasing U.S. aid even before a regional development program started.

As these proposals were made to the North, on 13 April 1965, joint RVN-US discussions agreed that the ARVN force levels were inadequate. The manning level was increased, to increase RVN infantry battalions from 119 (93 infantry, 20 Ranger, and 6 airborne) to 150. The new battalions were generally added to existing regiments, to avoid the need of creating more headquarters units. By the end of 1965, twenty-four were either in the field or in training areas.

McNamara proposes escalation, July

In July 1965, McNamara sent Johnson a set of notes proposing escalation of what he saw as a deteriorating situation in South Vietnam. "The situation in SVN is worse than a year ago (when it was worse than a year before that). After a few months of stalemate, the tempo of the war has quickened. . . . The central highlands could well be lost to the NLF during this monsoon season. Since June 1, the GVN has been forced to abandon six district capitals; only one has been retaken...The odds are less than even that the Ky government will last out the year. Ky is "executive agent" for a directorate of generals."

McNamara saw the correlation of forces between the ARVN and the VC is quite unfavorable. "The Govt-to-VC ratio overall is now only a little better than 3-to-1, and in combat battalions little better than 1.5-to-1." A historical rule of thumb for counterinsurgency has been that a 10 to 1 ratio is desirable, but, like all rules of thumb, it is not applicable to all situations. Even a critic of that generalization, "indeed, that ratio was often cited by critics of the U.S. policy in Vietnam", who cite a number of other revolutionary wars where the insurgency was defeated by less overwhelming ratios (e.g., Eritrea against Ethiopia) or where an acceptable goal was partition (e.g., Second Sudanese Civil War), cite the conventional wisdom as primarily relevant to situations of ideological insurgency against a central government, such as the Communist takeover of Vietnam, where the insurgents want complete victory. The current U.S. Army doctrine on counterinsurgency also recognizes there is no simple ratio, "During previous conflicts, planners assumed that combatants required a 10 or 15 to 1 advantage over insurgents to win. However, no predetermined, fixed ratio of friendly troops to enemy combatants ensures success in COIN...A better force requirement gauge is troop density, the ratio of security forces (including the host nation’s military and police forces as well as foreign counterinsurgents) to inhabitants...Twenty counterinsurgents per 1000 residents is often considered the minimum troop density required for effective COIN operations; however as with any fixed ratio, such calculations remain very dependent upon the situation." None of these sources, however, see a 3:1 to 1.5:1 as favorable.

McNamara also observed that the Administration's approach to air war against the North, Rolling Thunder, had not " produced tangible evidence of willingness on the part of Hanoi to come to the conference table in a reasonable mood. The DRV/VC seem to believe that SVN is on the run and near collapse; they show no signs of settling for less than complete takeover."

Autumn and winter, First Airmobile Battles: Ia Drang and Bong Son

Giap's new plan was to use three regiments, but with a new controlling divisional headquarters, across the neck of SVN, cutting the country in two. The division threatened the Plei Me special forces camp with one regiment, but put a second regiment across the road over which South Vietnamese forces, without helicopters, would have to drive to Plei Me from the larger base in Pleiku. Intelligence identified the presence, but at first not the position, of a third regiment, which could attack Pleiku if the reserve based there went to the assistance of Plei Me.

The PAVN preferred hit-and-run ambushes, or what they called "catch and grab." When their retreat was blocked, their next tactic was called "hugging the belt" the Americans hesitated to use artillery and gunships because of the risk of friendly fire casualties. The surprise attack would give a short window of opportunity before superior American mobility could be brought to bear. Moore's after-action reports suggested that "danger close" air and artillery could be a reasonable calculated risk when used competently.

The South Vietnamese recognized they were stretched too thin, and asked for U.S. help. The U.S. Field Force (corps equivalent) commander for the area, MG Stanley Larsen, told GEN Westmoreland that he thought the 1st Cavalry Division (Airmobile) was ready, and got permission for it to use its mobility to bypass the road ambushes. Since the PAVN along the road had planned to ambush trucks, there was not an issue of not being able to find the relieving troops. Helicopters could be heard, but their landing zones were unpredictable until they actually landed — fake landings were not uncommon. In the Battle of the Ia Drang, the first true airmobile force met PAVN regulars.

It should be noted that the PAVN's practice of listening for helicopters was realized by Harold Moore, promoted to brigade command after leading a battalion in the Ia Drang. In the larger Battle of Bong Son approximately a month later, which extended into 1966, Moore used obvious helicopters to cause the PAVN to retreat onto very reasonable paths to break away from the Americans — but different Americans had silently set ambushes, earlier, across those escape routes.