The inquiry focused on whether civilian and military personnel leaked classified details to reporters, particularly concerning dwindling US ammunition reserves, the newspaper reported on Friday.

The polygraph examinations took place last month after news outlets published several reports highlighting severe drops in key weapons supplies, including long-range missiles and Patriot air defence interceptors. US officials had pushed back on these reports, insisting their weapons stockpiles were more than sufficient.

In a statement to the NYT, Pentagon spokesperson Sean Parnell declined to address internal administrative or investigative actions directly, but emphasised that the department takes leaks of national security information “extremely seriously and investigates accordingly”.

“Securing classified information is critical to ensuring the security of the United States and of our troops deployed around the world,” Parnell added. The Joint Staff, which consists of between 1,500 and 2,000 military and civilian staff, plays a key role in coordinating operational strategy, policy and war planning with combat commands globally.

Sources familiar with the inquiry told the NYT that the aggressive push was designed not only to identify the individuals behind the disclosures, but also to deter potential future leakers. Legal and military experts say the scale of the investigation is unprecedented, as the top ranks of the US armed forces have never undergone widespread polygraph testing in modern history.

The move follows widespread reporting on how active military operations involving Iran have severely strained US weapon reserves, causing internal debates over the broader direction of the conflict. US President Donald Trump has repeatedly pushed officials to crack down on unauthorised disclosures. In addition to calling for strict enforcement, Trump has publicly branded critical media coverage regarding munition shortages and the administration’s handling of the conflict in Iran as “treasonous”. (Aljazeera)