Pentagon to probe defense officials’ use of Signal app

The Department of Defense’s acting inspector general plans to review the use of the Signal messaging app by defense officials, including U.S. Defense Secretary Pete Hegseth, according to a Thursday memo. In announcing the probe, the acting inspector general’s office specifically mentioned the incident last month in which Hegseth and other Trump administration officials used a Signal group chat to discuss a then-upcoming airstrike on Houthi terrorists in Yemen. A journalist from The Atlantic was added to the chat and he later made the incident public. National Security Adviser Mike Waltz has taken responsibility for inadvertently adding the journalist to the chat.

What are they looking for? The investigation will seek to determine how well Hegseth and others complied with Department of Defense policies and procedures by using a commercially available app for official business, wrote acting Inspector General Steven A. Stebbins. The probe follows up on a March 26 request from the chairman and ranking member of the Senate Armed Services Committee. The investigation will also look at whether officials complied with requirements for classification and records retention.

Catch me up. What’s Signal? Signal is a free, publicly available app. It uses end-to-end encryption and is reasonably secure for private use, but is probably inappropriate for top-secret conversations between government officials, according to the MIT Technology Review.

Dig deeper: Read Erick Erickson’s opinion column about how the Trump administration’s group chat was a bad but revealing mistake.