On March 11, a Signal user identified as “Michael Waltz” sent a connection request to the editor in chief of The Atlantic, who accepted. On March 13, the journalist was added to a Signal group titled “Houthi PC small group,” where accounts identified as senior officials (including “MAR,” “JD Vance,” “TG,” “Scott B,” “Pete Hegseth,” “John Ratcliffe,” and others) designated staff points of contact and discussed planned action against the Houthis.
On March 14, the group exchanged policy views and referenced “high side” classified inboxes; a message from “John Ratcliffe” contained information potentially related to current intelligence operations. On March 15 at 11:44 a.m., the “Pete Hegseth” account posted a “TEAM UPDATE” containing operational details for strikes on Yemen, including targets, weapons packages, timing, and sequencing; the first detonations were described as expected about two hours later. Around 1:55 p.m. eastern time, explosions were reported in Sanaa. After the strikes began, the group exchanged after-action messages and assessments. The National Security Council later confirmed the message chain was authentic and said it was reviewing how an inadvertent number was added.