The Pentagon is using polygraphs to hunt leakers, but the tests are more theatre than fact

Atlanta, In August 2026, government investigators subjected roughly 50 military officers and civilian employees on the Joint Staff to polygraph tests as part of an inquiry into press leaks about the Iran war and depleted US munitions, according to The New York Times.

The newspaper described the scope of the investigation as unprecedented in the modern military.

This is not the first time the Trump administration has used polygraphs in this way; in 2025, it directed that a wave of tests be administered across the executive branch to expose minor leaks.

As someone who has taken roughly a dozen polygraphs during my 27-year career with the CIA, I am wary of how the process is understood – and of the certainty its use can appear to convey.

Polygraphs carry an ominous, almost mythological reputation among Americans. The more familiar and unofficial term – lie detector tests – likely fuels that perception. Television crime dramas have done their part, too, often portraying the device as an oracle for uncovering the truth when conventional methods fail.

In those portrayals, the polygraph is not merely a tool – it's a window into the soul.

Among those entering government service, especially in national security, the greater anxiety is not the background check but passing the polygraph. My advice is always the same: Don't lie. It's the best – and perhaps only – guidance for a process that most assessments have concluded is a more subjective interpretation than empirical science.

Polygraphs are "pseudo-scientific" in that they measure physiological responses such as heart rate, blood pressure and perspiration. The assumption is that liars betray themselves through spikes in those signals. But this presumes a kind of psychological transparency that simply doesn't hold up. A person might sweat and tremble simply from fear, anger or frustration – not deceit.

There also are no specific physiological reactions associated with lying. The National Academy of Sciences in 2003, and the American Psychological Association in a 2004 review, concluded that the polygraph rests more on theatre than fact. A 2019 assessment reached the same conclusion.

Accordingly, polygraph results are not generally admissible in US courts. Only a handful of states – such as Georgia, Arizona and California – permit their use even under limited conditions. And they typically require that both parties agree to admission and a judge to approve it. Unconditional admissibility remains the exception, not the rule.

And yet, inside many national security agencies, polygraphs remain central to the clearance process – a fact I observed firsthand during my time overseeing personnel vetting and analytic hiring within the intelligence community.

While not treated as conclusive, polygraph results often serve as a filter.