Defense Secretary Pete Hegseth disclosed war plans in an encrypted group chat that included a journalist two hours before U.S. troops launched attacks against the Houthi militia in Yemen, the White House said on Monday, confirming an account in the magazine The Atlantic.
The editor in chief of The Atlantic, Jeffrey Goldberg, wrote in an article published on Monday that he was mistakenly added to the text chat on the commercial messaging app Signal by Michael Waltz, the national security adviser.
It was an extraordinary breach of American national security intelligence. Not only was the journalist inadvertently included in the group, but the conversation also took place outside of the secure government channels that would normally be used for classified and highly sensitive war planning.
Mr. Goldberg said he was able to follow the conversation among senior members of President Trump’s national security team in the two days leading up to the strikes in Yemen. The group also included Vice President JD Vance and Secretary of State Marco Rubio, Mr. Goldberg wrote.
At 11:44 a.m. on March 15, Mr. Hegseth posted the “operational details of forthcoming strikes on Yemen, including information about targets, weapons the U.S. would be deploying, and attack sequencing,” Mr. Goldberg wrote. “The information contained in them, if they had been read by an adversary of the United States, could conceivably have been used to harm American military and intelligence personnel, particularly in the broader Middle East.”
In an interview, Mr. Goldberg said that “up until the Hegseth text on Saturday, it was mainly procedural and policy texting. Then it became war plans, and to be honest, that sent a chill down my spine.”
Mr. Goldberg did not publish the details of the war plans in his article.
Mr. Hegseth, Mr. Goldberg wrote, said that “the first detonations in Yemen would be felt two hours hence, at 1:45 p.m. Eastern time. So I waited in my car in a supermarket parking lot.”
“If this Signal chat was real, I reasoned, Houthi targets would soon be bombed,” he added.
At around 1:55, initial airstrikes hit buildings in neighborhoods in and around Sana, Yemen’s capital, that were known Houthi leadership strongholds, according to Pentagon officials and residents. The strikes continued throughout that Saturday and into the next few days.
Mr. Hegseth, Mr. Goldberg wrote, declared to the group — which included the journalist — that steps had been taken to keep the information secret.
“We are currently clean on OPSEC,” Mr. Hegseth wrote, using the military acronym for operational security.
Several Defense Department officials expressed shock that Mr. Hegseth had put American war plans into a commercial chat group. They said that having this type of conversation in a Signal chat group itself could be a violation of the Espionage Act, a law covering the handling of sensitive information.
Revealing operational war plans before planned strikes could also put American troops directly into harm’s way, the officials said. And former F.B.I. officials who worked on leak cases described this as a devastating breach of national security. They spoke on the condition of anonymity to discuss a sensitive national security matter.
Former national security officials said that if personal cellphones were used in the group chat, the behavior would be even more egregious because of ongoing Chinese hacking efforts.
Senator Jack Reed of Rhode Island, the ranking Democrat on the Armed Services Committee, said that the “story represents one of the most egregious failures of operational security and common sense I have ever seen.”
“Military operations need to be handled with utmost discretion and precision, using approved secure lines of communication, because American lives are on the line,” he added.
Republican senators faced a barrage of questions. Many said they were concerned, but most were withholding judgment until they could receive a full briefing.
“It appears that were mistakes were made, no question,” said Senator Roger Wicker, Republican of Mississippi and the chairman of the Armed Services Committee. “We’ll try to get to ground truth and take appropriate action.”
Mr. Trump, speaking to reporters at the White House, said that he had no knowledge of the article in The Atlantic. “I don’t know anything about it,” he said, adding, “You’re telling me about it for the first time.”
The Pentagon referred questions about the article to the National Security Council. Mr. Hegseth was traveling to Hawaii on Monday, his first stop on a weeklong trip to Asia. He spoke to reporters traveling with him after landing in Hawaii, called Mr. Goldberg a “so-called journalist” and, when pressed, said that “nobody was texting war plans, and that’s all I have to say about that.”
But the White House appeared to contradict him. “At this time, the message thread that was reported appears to be authentic, and we are reviewing how an inadvertent number was added to the chain,” Brian Hughes, the National Security Council spokesman, said in an emailed statement. He called the thread “a demonstration of the deep and thoughtful policy coordination between senior officials.”
The State Department spokeswoman, Tammy Bruce, said at a press briefing that she would not comment on Mr. Rubio’s “deliberative conversations,” and directed further questions to the White House.
The group chat also included a dissent from Mr. Vance, who called the timing of the Yemen operation a “mistake.” He and Mr. Hegseth both argued in the chat that European countries benefited from the U.S. Navy’s efforts to protect shipping lanes from Houthi attacks.
“I am not sure the president is aware how inconsistent this is with his message on Europe right now,” Mr. Vance wrote before the operation. He said he was “willing to support the consensus of the team and keep these concerns to myself.”
But he added that “I just hate bailing Europe out again.”
Mr. Hegseth replied: “I fully share your loathing of European free-loading. It’s PATHETIC.” But, he said, “I think we should go.”
During his first term, Mr. Trump repeatedly said Hillary Clinton should have been imprisoned for using a private email server to communicate with her staff and others while she was secretary of state. Mr. Waltz, for his part, posted on social media in June 2023: “Biden’s sitting National Security Advisor Jake Sullivan sent Top Secret messages to Hillary Clinton’s private account. And what did DOJ do about it? Not a damn thing.”
On Monday, Mrs. Clinton reposted the Atlantic story on social media with one comment: “You have got to be kidding me.”
Michael Crowley and Adam Goldman contributed reporting.