Why America’s Leaders Ignored Shockingly Prescient Sigma War Games on Vietnam

Hoover Institution (Stanford, CA) - In the early 1960s, America was slowly marching into an all-out war in Vietnam. Historians have questioned the reasons for US involvement in the region ever since.

The Sigma War Games, a series of politico-military war games run by the Pentagon's Joint Staff during the 1960s, sought to understand the unfolding conflict in Southeast Asia. These games, which involved top figures from the Johnson administration-including National Security Advisor McGeorge Bundy, Air Force General Curtis LeMay, and Chairman of the Joint Chiefs of Staff Earle Wheeler-offered a chillingly accurate forecast of the war's potential trajectory.

These games accurately predicted the dates that America would launch a bombing campaign and land Marines at Da Nang Air Base.

The games also indicated the United States would need to devote as many as 500,000 troops to the Vietnam War, something that came to pass by the end of 1967.

Finally, the games accurately predicted the massive domestic discontent generated by America's involvement in Vietnam, many years before that discontent reached its peak.

"These games are such a huge historical puzzle," Jacquelyn Schneider, Hoover fellow and director of the Institution's Wargaming and Crisis Simulation Initiative, said. "I work on how games influence foreign policy, and these have all the ingredients of a war game that really should have mattered but didn't."

The event draws from documents contained in Hoover's new Wargaming and Crisis Simulation Initiative Collection. The collection includes original documents detailing six of the Sigma war games, conducted between 1962 and 1967.

On Tuesday, October 8, 2024, Schneider brought together Hoover senior fellow H.R. McMaster; Mai Elliott, award-winning author of The Sacred Willow and a RAND Corporation study on the Vietnam War; and Mark Moyar, director of Hillsdale College's Center for Military History and Strategy, to discuss why the conclusions of the Sigma war games went unheeded.

McMaster, who wrote a book on this very question called Dereliction of Duty, spoke to the audience about how events that had little or nothing to do with the actual situation in South Vietnam and the wider region started to influence how decisions were made.

Schneider suggested that the feeling early in the Kennedy administration that the situation in Southeast Asia could evolve and expand rapidly probably motivated the Sigma war game series.

"Someone in the Pentagon had to have said 'something in southeast Asia is important enough that we are going to develop a whole war game series on it,'" Schneider said.

When President John F. Kennedy took office in 1961, he represented "generational change" compared with former president Dwight D. Eisenhower, McMaster said.

But Kennedy made decisions differently than his predecessor, who had been the leader of American and allied troops during the Second World War.

"Kennedy had a much more informal decision-making style," McMaster said. "There is no systematic examination of different courses of action."

And with the failure of the Bay of Pigs invasion of Cuba in April 1961, Kennedy became deeply distrustful of the US Joint Chiefs of Staff even though, as McMaster explained, the invasion should have instead made Kennedy recoil against its plotters in the Central Intelligence Agency (CIA).

Two significant events occurred in 1963 that changed the trajectory of the US involvement in Vietnam; a military coup that led to the death of South Vietnam's president, Ngô Đình Diệm, on November 2 and the assassination of President Kennedy on November 22.

When President Lyndon B. Johnson took office, McMaster said, continuity with Kennedy's national security apparatus was a primary concern.

"LBJ doesn't want to change out everyone who can't be trusted," McMaster said.

He continued to convene what would later be called the "Tuesday Lunch Group," involving Bundy, LeMay, and Wheeler, along with Secretary of Defense Robert McNamara, who McMaster called "the dude who has answers for everything."

By early 1964, several of the Sigma war games had been completed, offering the administration ominous conclusions, but they were ignored.

"This is the setup for some really bad decision making in 1964 and 1965," McMaster said.

To illustrate how difficult decision making proved to be for the Johnson administration during this period, the talk involved Schneider live polling the audience via smartphone application on three scenarios pulled straight from the Sigma war games.

In the first, North Vietnamese Leader Ho Chi Minh addresses the UN General Assembly in New York and presents photos, some of which may be fake, of civilians suffering the impact of the US military's mass bombing campaign.

Attendees were given three options. In response, if in charge, would they:

A) Go to the UN to refute Ho Chi Minh's claims

B) Ignore his visit and downplay US involvement

C) Send President Johnson to South Vietnam for a press tour

Nearly half of participants in the room selected option A.

Speaking on the narrative of the war and how it influenced American leadership, Mai Elliott pointed out that the few American officials who sought out the views and sentiments of the Viet Cong were ignored.

For instance, Elliott said that the RAND Corporation conducted interviews with nearly 150 captured Viet Cong fighters and some defectors, publishing their findings in March 1965.

"Their conclusions were that the US was facing a formidable enemy because the (Viet Cong) were highly motivated, they felt they were fighting another occupier-the 'new colonialists' who were replacing the French to dominate Vietnam," Elliott said.

Compounding this view was the general sentiment in South Vietnam, which saw the Saigon government as "a puppet" of the United States.

Elliott said RAND presented these findings to US Assistant Secretary of Defense John McNaughton in 1964, but he couldn't believe them.

"Gentlemen, if what you're telling me is true, we are fighting on the wrong side of this war," Elliott said, citing what McNaughton replied to RAND researchers after reading the report.

But by the time the report arrived, America was already deep into the war following the Gulf of Tonkin incident of August 2, a pair of naval engagements between the United States and North Vietnam used by the Johnson administration to justify a major increase in American involvement in the conflict.

There were other reasons the war games and other intelligence were ignored.

Moyar argued that President Johnson thought the decision to fight in Vietnam was supported by the logic that it "was going to be awful but the alternative is way worse. Dominoes will fall all over Asia."

It was a complex set of decisions. As McMaster explained, "The debate was far more complicated than to bomb or not bomb, escalate or not escalate."

There were others challenges too.

Each branch of the armed services and the intelligence agencies had different beliefs about how to fight in Vietnam; interservice rivalries and competing political agendas often diluted the information that Johnson used in his decisions.

Also, when it came to bombing the Vietnamese countryside to disrupt Viet Cong supply lines and deny them safe harbor in villages, McMaster and Elliott both said the US misunderstood the impact of all the destruction.

The bombing didn't compel the Viet Cong to withdraw from the South, nor did it persuade the civilian population to stop supporting them. Instead, it pushed them closer together.

It's another conclusion RAND made during the war and submitted to White House officials that was ignored.

Schneider cautioned attendees against concluding that the war games mattered simply because they got the future right, because that isn't the best way to interpret the value of war games.

"As someone who uses games as part of my research, I think we should not think of whether a game can predict the future accurately as whether it is a good game or a bad game," she said.

"Games are a way in which we understand the uncertainty of the world we live. As historians and political scientists, looking at games from a historical point of view, they help us understand the reasoning behind decisions and the belief people bring into the important questions of the day."

Public link

Please use the above public link if you want to share this noodl on another website.