Isegoria

The Gulf of Tonkin Incident involved a second incident in the gulf, two days after a minor clash:

When the contacts appeared to turn away at 6,000 yards, Maddox’s crew interpreted the move as a maneuver to mark a torpedo launch. The ship’s sonar operator reported a noise spike — not a torpedo — which the Combat Information Center (CIC) team mistook for report of an incoming torpedo.

Both U.S. ships opened fire on the radar contacts, but reported problems maintaining a lock on the tracking and fire control solution. The first reports of the encounter from the destroyers reached the White House at 1000 EDT. Two hours later, Captain Herrick reported the sinking of two enemy patrol boats.

With this information, back in Washington President Johnson and his advisers considered their options. By 1400 hours EDT, the president had approved retaliatory strikes against North Vietnamese naval bases for the next morning, August 5, at 0600 local time, which was 1900 EDT on August 4 in Washington. In the meantime, aboard Turner Joy, Captain Herrick ordered an immediate review of the night’s actions.

His assessment of the evidence now raised doubts in his mind about what really had happened. He reported those doubts in his after action report transmitted shortly after midnight his time on August 5, which was 1300 hours August 4 in Washington.

Herrick requested aerial reconnaissance for the next morning to search for the wreckage of the torpedo boats he thought he had sunk. Both of these messages reached Washington shortly after 1400 hours EDT. Neither Herrick’s doubts nor his reconnaissance request was well received, however. The Pentagon had already released details of the “attack,” and administration officials had already promised strong action. Then, everyone’s doubts were swept away when a SIGINT intercept from one of the North Vietnamese torpedo boats reported the claim that it had shot down two American planes in the battle area.

McNamara and the JCS believed that this intercept decisively provided the “smoking gun” of the second attack, and so the president reported to the American people and Congress.

A subsequent review of the SIGINT reports revealed that this later intercept — McNamara’s “smoking gun” — was in fact a follow-on, more in-depth report of the August 2 action. Moreover, the subsequent review of the evidence exposed the translation and analysis errors that resulted in the reporting of the salvage operation as preparations for a second attack. In fact, the North Vietnamese were trying to avoid contact with U.S. forces on August 4, and they saw the departure of the Desoto patrol ships as a sign that they could proceed to recover their torpedo boats and tow them back to base.

They never intended to attack U.S. forces, and were not even within 100 nautical miles of the U.S. destroyers’ position at the time of the purported “second engagement.”

NSA officials handed the key August SIGINT reports over to the JCS investigating team that examined the incident in September 1964. Those same reports were shown to the select congressional and senate committees that also investigated the incident. The entirety of the original intercepts, however, were not examined and reanalyzed until after the war.

The 122 additional relevant SIGINT products confirmed that the Phu Bai station had misinterpreted or mistranslated many of the early August 3 SIGINT intercepts. With that false foundation in their minds, the on-scene naval analysts saw the evidence around them as confirmation of the attack they had been warned about.

Those early mistakes led U.S. destroyers to open fire on spurious radar contacts, misinterpret their own propeller noises as incoming torpedoes, and ultimately report an attack that never occurred.

Despite the on-scene commanders’ efforts to correct their errors in the initial after-action reports, administration officials focused instead on the first SIGINT reports to the exclusion of all other evidence. Based on this, they launched the political process that led to the war’s escalation.

The Gulf of Tonkin Incident and many more recent experiences only reinforce the need for intelligence analysts and decision makers to avoid relying exclusively on any single intelligence source — even SIGINT — particularly if other intelligence sources are available and the resulting decisions might cost lives. Signals Intelligence is a valuable source but it is not perfect. It can be deceived and it is all too often incomplete. Like all intelligence, it must be analyzed and reported in context. People are human and make mistakes, particularly in the pressure of a crisis or physical threat to those they support. Perhaps that is the most enduring lesson from America’s use of SIGINT in the Vietnam War in general and the Gulf of Tonkin Incident in particular.

(Hat tip to our Slovenian guest.)

While discussing The Defence of Duffer’s Drift, commenter Alex J. asked, How modern is the modern foxhole?

According to Wikipedia, early in World War II, during the fighting in North Africa, U.S. forces employed the slit trench — a very shallow excavation allowing one man to lie horizontally while shielding his body from nearby shell bursts and small arms fire — but after the Battle of Kasserine Pass, U.S. troops increasingly adopted the modern foxhole — a vertical, bottle-shaped hole that allowed a soldier to stand and fight with head and shoulders exposed.

If we look back at the U.S. War Department’s Newsmap, from Monday, October 26, 1942, it proclaims that foxholes are lifesavers:

Whether he is serving in the rocky wastes of Egypt or in the jungles of New Guinea, the American infantryman quickly discovers that the ground is his best friend in time of trouble. It is a lesson that no soldier ever learns too soon, for in the degree that it becomes his habit to seek protection even when halted for a few minutes, and to study the nature of cover and the elements of personal protection while he is in training, he increases his chance to survive in combat and to defeat the enemy.

The Basic Field Manual tells the story: You are most exposed to fire when you are standing, much less when you are prone, and best protected when you are below the surface of the ground. For example, under artillery shell fire, ten out of ten men would be hit by shell fragments if they were standing. Only six of the ten would be hit if all were prone. Only one would be hit if they were in shallow trenches or in foxholes.

Yet the swing back to intensive training in the nature and need of hasty field fortifications is a relatively new thing. During the first two years of the present war, the value of improvised works was greatly discounted, at first because of the emphasis on permanent fortifications, and subsequently because of the feeling that due to the influence of the high velocity weapons, the days of fixed positional warfare were over for good. From necessity, troops who were virtually without knowledge of how to dig and revet a trench of the 1914–18 variety soon learned how to scratch out air-raid trenches. Within the last year many occasions have arisen — in Libya, in Bataan, in Malaya and in Alaska — when a capacity to dig in quickly meant the difference between saving or losing a situation.

Very quickly the new technic of hasty fortification, as shaped by the need for protection against the tank and the airplane, has become standardized in line with the commonsense principle of achieving the maximum of protection in the minimum of time. Speed is the essence of today’s entrenching methods as it is of the modern offensive. The old type of trench — a much more elaborate affair — did not give adequate concealment from air and ground reconnaissance. Consequently, it is a conspicuous target for heavy concentrations of fire from aircraft and from ground weapons.

The new methods are designed to make all types of bombardment relatively ineffective by diffusing the target and giving greater individual protection to the soldier. Moreover, armored vehicles are not effective against infantry which they cannot see.

The special requirements of today’s warfare are therefore met when the soldiers are located in small one or two-man foxholes. To add to the enemy’s confusion, use may be made of decoy positions constructed in the general area of those which are to be occupied. Care must be taken to apply the same camouflage to the dummy positions as to the genuine ones.

Whenever our troops halt anywhere within range of Jap or Nazi bombers, they turn at once to give themselves and their weapons individual protection. If it’s a short halt, they use the natural protection of the ground — bumps, ditches, shell holes, ravines or depressions of any kind. But if it’s a longer halt — though less than six hours in an assembly area before an attack — then each man digs himself an individual prone trench. It can be done in a few minutes. That kind of a shelter gives a solider two advantages — a chance to rest and reasonable protection from bomb, mortar and shell fragments and small-arms fire. The prone trench, however, is not suitable protection against a tank attack.

If an outfit is to halt for more than five or six hours, it goes to work at once on standing-type one-man foxholes. These will protect the soldier against all bombs and shells, excepting direct hits, as well as small-arms fire. If the foxhole is dug deep enough to leave a clearance of two feet between the soldier and the surface of the ground, it is possible by crouching to obtain protection against the average enemy tank.

In digging this type of foxhole, the sod is put to one side. The rest of the dirt is then piled irregularly around the edges of the hole. When digging is completed, the sod is used to cover the rest of the dirt.

To quote the manual: “You must learn to study the terrain in order to appreciate the cover… that appears flat to the untrained eye.”

The wise foot soldier does not wait until he moves into the combat area before developing a practiced eye. He begins wherever he is doing duty, upon the ground over which he moves in his daily training.