Communist attacks on the destroyer USS Maddox (DD 731) in the Gulf of Tonkin in August 1964 and the killing of American service personnel in South Vietnam later in the year and in early 1965 convinced American military leaders that the outbreak of war was imminent.

It was apparent that rather than buckling under U.S. military pressure, Hanoi had decided to take the offensive. CINCPAC noted in March 1965 a “shift of communist tactics” intended to “bring about the disengagement of the U.S. in South Vietnam.” In a prescient statement, Admiral Sharp concluded that the North Vietnamese felt that “if they can kill Americans, harass U.S. personnel, and destroy U.S. facilities the American people will, in time, become so tired of the war that we will abandon our efforts there.”

Chief of Naval Operations Admiral David L. McDonald called on naval intelligence for an “honest, hard NON-EQUIVOCAL assessment” of enemy intentions.” Rear Admiral Rufus L. Taylor, the Director of Naval Intelligence, responded with an appraisal that suggested China was emboldened by the political disarray in South Vietnam and weak U.S. counteractions to Communist attacks. The underlying assumption of Taylor’s report was that China rather than North Vietnam was the prime motivator for bellicose actions in Southeast Asia. Taylor considered the Chinese determined to help the Vietnamese and Laotian Communists secure a victory over the United States and its allies. The admiral pointed to the recent buildup of military forces in southern China and the delivery of war materials to Hanoi as a clear sign of Chinese intentions. The Navy’s top intelligence officer took the opportunity to make his own pitch for robust U.S. action, observing that “if we think it is important to us, as I do, to keep Southeast Asia out of Chinese Communist hands, we must commit ourselves to extensive hostilities in that area.”

Impossible to see by the pilots who led the reconnaissance mission from the carrier Enterprise (CVAN 65), these ten North Vietnamese surface-to-air missile emplacements were found by skilled photo interpreters. (Naval History and Heritage Command image)

A year’s experience with the Yankee Team aerial reconnaissance program in Laos had enabled the Navy’s intelligence establishment to hone its procedures for collecting, processing, and disseminating tactical intelligence even before the onset of the Rolling Thunder bombing campaign against North Vietnam in the spring of 1965. Seventh Fleet Commander Vice Admiral Johnson, however, realized that his carrier and surface forces needed even more precise information on potential targets and enemy air defenses ashore, the area’s geography and hydrography, and the operating environment.

The Fleet Intelligence Center Pacific (FICPAC) in Hawaii, employing 270 personnel by 1967, stepped up to provide the aviation and surface ship combat units with updated maps, charts, targeting aids, pilot escape and evasion guides, and computerized orders of battle. The center also interpreted aerial reconnaissance imagery and produced an average of 27,000 photo prints each month in support of photo intelligence reports. The Naval Weather Center on Guam produced updated information on the climatological and weather characteristics in the Gulf of Tonkin. By the start of the Rolling Thunder bombing campaign in March 1965, naval intelligence had provided relevant and updated materials to the fighting squadrons and warships deployed off North Vietnam.

On the negative side, technology was such in the 1960s that it might take days for couriers to deliver raw photographic and audio information from the field, process it (including translating the communications intercepts from Vietnamese to English), interpret it, and send the finished product to the combat commands. On too many occasions, the intelligence product arrived too late for its optimum combat use. Excessive compartmentalization by the intelligence agencies of highly classified and sensitive information also sometimes prevented the combat commands from receiving a comprehensive picture of the enemy situation.

Much of the information on enemy defenses and weather in the operational area that would be provided to the Navy’s intelligence analysis centers during the war came via the NSA, one of whose primary objectives was to “extend the eyes of American air surveillance.” The agency’s signals intelligence programs “revealed information about Vietnamese tracking of hostile and friendly aircraft over Laos, North Vietnam and the Gulf of Tonkin, SAM [surface-to-air missile] order-of-battle details, bomb damage reports, airfield status, and other data.” NSA cryptologists gathered information on the weather over North Vietnam from intercepts and passed it on to naval intelligence and hence the fleet. The agency’s reports, called “Songbirds,” relayed information on the location of downed fliers and attempts by the enemy to capture them. The Navy, however, generally found that the intercepts could not be translated fast enough for a timely response by the fleet’s search and rescue forces.

Featured image: A U.S. Navy Photographic Intelligenceman (PT) aligns consecutive panoramic photographs to assemble a mosaic of a target area. (National Archives and Records Administration)

P.S. The Intelligence Specialist (IS) rating was established on July 26, 1975 by combining the Photographic Intelligenceman (PT) rating (established on April 10, 1957) and parts of the Yeoman (YN) rating.

Source: Vietnam Daybook Vol 21 4 Final