In August 2026, government investigators conducted polygraph tests on approximately 50 military officers and civilian staff at the Joint Staff as part of an investigation into press leaks related to the Iran war and the depletion of U.S. military supplies, according to The New York Times. This move was described as an unusual and expansive effort within the modern military. The use of polygraphs—devices that measure physiological responses like heart rate, blood pressure, and sweating—has long been a controversial method for detecting deception. This is not the first time the Trump administration has used polygraphs to probe leaks. In 2025, the administration ordered widespread polygraph testing across the executive branch to uncover minor leaks. However, experts have long questioned the reliability of polygraphs. A CIA veteran who has taken over a dozen polygraphs in his career noted that while the devices track physical responses, there are no definitive physiological signs of lying. Scientific reviews from 2003 and 2004 by the National Academy of Sciences and the American Psychological Association concluded that polygraphs are more theatrical than factual. A 2019 assessment reaffirmed these findings. Despite their lack of legal standing in U.S. courts—where only a few states allow their use under strict conditions—polygraphs remain a key tool in the clearance process at many national security agencies. A candidate's nervousness or an examiner's judgment that a response is evasive can halt the hiring process. In some cases, even minor physiological reactions to questions about past drug use or foreign contacts have led to the suspension of clearances, even when no wrongdoing was confirmed. The power of polygraphs lies in their psychological impact. In some instances, an examiner's suggestion that a chart shows an unusual response has led otherwise strong candidates to reveal details they hadn't intended to share—such as minor security lapses, old relationships, or past drug use. These confessions, while not necessarily disqualifying, can affect how someone's trustworthiness is judged. The impulse to investigate leaks is not exclusive to any one administration. When an embarrassing disclosure appears in the press—contradicting official statements or revealing internal dissent—the White House often vows to identify and punish the source. Polygraphs are often part of this process. During his first term, President Trump intensified efforts to uncover leaks and dissent within his administration. Policies were revised to make it easier to obtain journalists' communications, and polygraphs were reportedly used to pressure officials suspected of speaking to the press. These practices have continued and expanded since 2025. At the Pentagon, new policies have limited unescorted press access, reduced office space for major media outlets, and favored news networks with ideological alignment. The boundary between legitimate leak prevention and press surveillance or suppression has become increasingly unclear. At agencies like the Department of Homeland Security and the FBI, polygraphs are reportedly used more frequently and more harshly to identify internal critics. Even "cold cases," such as the leak of the Supreme Court’s Dobbs decision, have been reopened, despite earlier investigations yielding no clear source. Not all leaks are treated equally. Disclosures that support official narratives or offer strategic benefits may be quietly overlooked, even if unauthorized. Leaks that embarrass senior officials or reveal dysfunction, however, often lead to formal investigations. In 2003, the leak of CIA officer Valerie Plame’s identity—a move seen as retaliation for her husband’s criticism of the Iraq War—triggered a federal investigation and led to the conviction of a White House aide. The public rarely learns the outcomes of most leak investigations, and direct accountability is rare. The Pentagon’s use of polygraphs is unlikely to stop all leaks, but it may create a chilling effect that discourages open communication within the military and diverts resources from core security concerns. While such efforts may reduce unauthorized disclosures, they could also weaken institutional resilience. Historically, strict internal enforcement has been linked to declining morale and reduced information sharing, which can hinder the ability to respond to complex threats. Researchers suggest that artificial intelligence might one day offer reliable tools for detecting deception, but the technology is not yet ready for practical use.