President Donald Trump’s National Security Adviser Mike Waltz has found himself in the middle of a political firestorm after mistakenly adding The Atlantic’s editor-in-chief to a group chat about U.S. plans to strike Yemen on the encrypted messaging app Signal.
Now, Trump and certain media outlets are defending Waltz, while Defense Secretary Pete Hesgeth denied the legitimacy of the leaks, despite the administration confirming their validity.
Lawmakers on both sides of the aisle are calling for Waltz to step down, while several top Trump administration officials were blasted over the leak during a Senate Intelligence Committee hearing on Tuesday morning.
Here’s what you need to know about Waltz:

The ‘Houthi PC Small Group Chat’
The Atlantic’s Jeffrey Goldberg reported Monday that Waltz appeared to have added him to a group chat titled “Houthi PC small group” on Signal. The thread also appeared to include top White House officials, including Vice President JD Vance and Defense Secretary Pete Hegseth.
At first, Goldberg wasn’t sure if the group chat was real. But soon enough, officials started sending the planned times of U.S. strikes on Yemen — and Goldberg realized they lined up perfectly.
National Security Council spokesperson Brian Hughes confirmed to The Atlantic that the group chat “appears to be an authentic message chain.”
Both Democrats and Republicans are now calling for action in the wake of the leak.
Pete Buttigieg, who served as Transport Secretary under Joe Biden, called the leak “the highest level of f***up imaginable.”
Republican Representative Don Bacon told Axios: “None of this should have been sent on non-secure systems.”
Waltz previously served in the House and U.S. military
When Trump tapped him for National Security Adviser, Waltz was a Congressman representing Florida’s 6th district. Waltz resigned in January to take on his new role under Trump.
When announcing his pick, Trump called Waltz “a nationally recognized leader in National Security, a bestselling author, and an expert on the threats posed by China, Russia, Iran, and global terrorism.”
“Mike has been a strong champion of my America First Foreign Policy agenda, and will be a tremendous champion of our pursuit of Peace through Strength,” he added.
Waltz was elected to the House in 2018, taking Ron DeSantis’s spot after he was elected Florida’s governor. He served on the Armed Services, Intelligence, and Foreign Affairs House committees. He also served on the House China Task Force.
While Waltz was a key critic of the Biden administration, he also diverged from Trump on some issues — including the TikTok ban. Waltz called the app “CCP spyware” in 2023 and voted to ban it.
But in January, Waltz backed Trump as he vowed to save TikTok, calling the app “a great platform for him and his campaign to get his America First message out.”
Before he was a lawmaker, Waltz served 27 years in the Army and National Guard. He retired as a colonel and was the first Green Beret elected to Congress.