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

In August 2026, numerous military personnel and civilian employees at the Joint Staff underwent polygraph tests amid an investigation into leaks regarding the Iran war and depleted U.S. munitions, reported by The New York Times. This extensive probe marked a significant departure from previous instances. The administration's implementation of polygraph examinations has a history dating back to 2025, when the directive was issued to conduct screenings across the executive branch to detect minor leaks.

Based on personal experiences spanning three decades with the CIA, the author cautions against the misconceptions surrounding polygraph tests, often referred to as lie detector tests. The media's portrayal of the device as an oracle for revealing the truth has contributed to its mystique in popular culture. Despite their ominous reputation, polygraphs are, in fact, pseudo-scientific tools that gauge physiological responses such as heart rate, blood pressure, and perspiration, presuming that liars exhibit distinct reactions.

However, these assumptions overlook the psychological factors that can trigger similar physical responses unrelated to deceit. The National Academy of Sciences and the American Psychological Association have both concluded that the polygraph is more reliant on theatrical elements than empirical evidence. Consequently, polygraph results usually lack admissibility in U.S. courts, with only a limited number of states permitting their use under restricted conditions.

Nevertheless, within national security agencies, polygraphs remain integral to the clearance process, often functioning as a preliminary filter rather than a definitive verdict. While they may not conclusively identify truth-tellers, polygraph results can influence hiring decisions by highlighting areas of concern that may require further scrutiny.

The persistent use of polygraphs in leak investigations underscores the ongoing tension between maintaining national security and preserving the integrity of journalistic endeavors.