The leak happened as the US launched strikes against Iran-backed Houthis and despite a crackdown on sensitive information leaks.
Top national security officials in the Trump administration, including Defence Secretary Pete Hegseth, have reportedly sent war plans for upcoming military strikes against the Houthis to a group chat in a messaging app that included The Atlantic’s editor-in-chief, the magazine reported in a story published on Monday.
The US National Security Council stated that the text chain “appears to be authentic”.
Editor-in-chief Jeffrey Goldberg reported that the material in the text chain “contained operational details of forthcoming strikes on Iran-backed Houthis in Yemen, including information about targets, weapons the UK would be deploying, and attack sequencing.”
It was not immediately clear whether the specifics of the military operation were classified, but they often are and, at the very least, are kept secure to protect service personnel and operational security.
The UK has carried out airstrikes against the Houthis since the militant group began targeting commercial and military vessels in the Red Sea in November 2023.
Just two hours after Goldberg received the details of the attack on 15 March, the UK started launching a series of airstrikes against Houthi targets in Yemen.
The National Security Council said in a statement that it was investigating how a journalist’s number was added to the chain in the Signal group chat.
Government officials have used the Signal app for organisational correspondence, but it is not classified and might be open to hacking despite providing end-to-end encryption.
The information leak occurred as Hegseth’s office had just announced a crackdown on leaks of sensitive information, including the potential use of polygraphs on defence personnel to determine how reporters have received information.
Sean Parnell, a spokesman for Hegseth, did not immediately respond to requests for comment on why the defence secretary posted war operational plans on an unclassified app.
