Pentagon watchdog launches probe into Defense Secretary Hegseth's Signal leak

The Pentagon inspector general announced Thursday that it has launched an investigation into the leak of attack plans by senior officials on a commercial messaging app.

The senior Republican and Democrat on the Senate Armed Services committee requested the investigation after The Atlantic reported detailsfor the March 15 attack on Houthi militants in Yemen had been discussed by senior officials, including Defense Secretary Pete Hegseth, on the encrypted app Signal. Mike Waltz, President Donald Trump’s national security advisor, included The Atlantic's editor in the chat on the encrypted app Signal.

“The objective of this evaluation is to determine the extent to which the Secretary of Defense and other DoD personnel complied with DoD policies and procedures for the use of a commercial messaging application for official business,” Steven Stebbins, the acting Pentagon inspector general wrote in a memo. “Additionally, we will review compliance with classification and records retention requirements.”

Hegseth has denied that he revealed sensitive information in the chat when he wrote in about the specific timing of attack by Navy pilots in F-18 warplanes. Several current and former Pentagon officials have told USA TODAY that the specificity of the information about imminent attacks that Hegseth released is among the most closely guarded information in the military.

The investigation will be conducted in Washington and Tampa, at U.S. Central Command headquarters, Stebbins wrote.

Mollie Halpern, a spokesperson for the Department of Defense inspector general, said the probe was an evaluation, not an investigation. An evaluation is a "systematic and independent assessment of the design, implementation or operation of programs or policies," whereas an investigation "may involve alleged violations of criminal or civil laws as well as administrative requirements," she said.

Also Thursday, Trump fired several National Security Council staffers who apparently were associated with Signal chat blunder.