The Signal chat leak of US strike plans on Yemen

Investigations followed. Judge James Boasberg ordered agencies to preserve Signal messages sent from March 11 to 15,^[12] and the top Republican and Democrat on the Senate Armed Services Committee asked for an investigation.^[13] On April 3 the Pentagon's acting inspector general, its internal watchdog, opened a review of Hegseth's use of Signal.^[14] Later that month CNN reported that Hegseth had shared detailed plans for the operation in a second Signal chat, on his personal phone, that included his wife, his brother and his lawyer.^[15] The AP reported that he had an internet line that bypassed Pentagon security protocols set up in his office to use Signal on a personal computer.^[16] In June the watchdog was examining whether aides had been asked to delete his Signal messages, the AP reported.^[17]

Waltz paid the price first. On May 1, 2025, Trump announced that he would nominate Waltz as ambassador to the United Nations, after reports that he was leaving the national security adviser's job.^[4][18] The day before, Waltz had been photographed at a Cabinet meeting using a Signal-like app that can archive messages.^[19] At his confirmation hearing in July he faced questions about the chat and insisted that he had not technically been fired.^[20]

The inspector general reported in December 2025, after a more than eight-month investigation. The watchdog concluded that the information Hegseth shared was classified and that his use of Signal violated department policy and risked compromising sensitive information, which could have endangered troops and their mission.^[6][5] The Pentagon pointed to the conclusion that Hegseth had the authority to declassify the strike information and called the report a "total exoneration."^[5] The strikes themselves are followed in the arc on the Houthis' attacks and the US strikes on Yemen.