Former national security adviser Michael Waltz in the Cabinet Room of the White House in March. Shawn Thew / EPA / Bloomberg ...

President Donald Trump ousted his national security adviser, Michael Waltz. Trump’s use of an 18th century law for ...

Waltz inadvertently added The Atlantic's editor-in-chief to a group thread discussing sensitive national security matters.

The fired national security adviser engaged in intense coordination with Israeli Prime Minister Benjamin Netanyahu about ...

Waltz’s ouster on Thursday was cushioned by his appointment as President Donald Trump’s ambassador to the United Nations.

This is the first significant personnel overhaul of top White House aides, and the kind of shake-up President Trump has ...

The national security advisor and his deputy are reportedly leaving their posts, after the former accidentally invited a ...

Trump said he's nominating Michael Waltz to be ambassador to the United Nations, while Secretary of State Marco Rubio will ...

The ousted national security adviser will be nominated for U.N. ambassador, a less influential post, after his ...

The app Waltz was using appeared to be “TM SGNL,” a modified version of Signal that retains and archives messages to comply ...

Waltz did not require congressional approval to serve earlier as President Donald Trump’s national security adviser ...