Who is Matt Pottinger? Former Trump national security official testifes about Jan. 6

Matthew Pottinger, a former National Security Council official, is testifying before the House Jan. 6 committee's prime time public hearing.

But some are wondering, exactly who is Pottinger?

Pottinger started his time in the Trump White House in 2017 and resigned from his post at the National Security Council shortly after the Jan. 6 insurrection in 2021. In February 2021, Pottinger told "Face the Nation" moderator Margaret Brennan it "was the moment where I felt that it was appropriate for me to go."

He has testified before the committee before. During a June hearing, the committee played part of Pottinger's previously recorded video testimony, during which he said he decided to resign after former President Donald Trump tweeted that former Vice President Mike Pence should have had more courage.

"I read that tweet. And made a decision at that moment to resign," Pottinger said in the recorded testimony. "That's where I knew that I was leaving that day, once I had read that tweet."

Pottinger is a distinguished visiting fellow at the Hoover Institution, which is a public policy think tank that conducts research with a goal of addressing challenges like educational outcomes and expanding economic prosperity.

Before his role in the White House, Pottinger was a U.S. Marine and fought in Iraq and Afghanistan during three combat deployments between 2007 and 2010, according to his bio on the Hoover Institute website. He also spent time in China as a reporter for Reuters and the Wall Street Journal.

He founded and led a risk consultancy focused on Asia and also ran Asia research for a New York investment fund. In the White House, he led the Trump administration's work on the Indo-Pacific region – particularly its shift on China policy. As a NSC official, he coordinated the full spectrum of national security policy, according to the Hoover Institute.

Trump White House deputy press secretary Sarah Matthews is also testifying at Thursday's primetime hearing from the House committee. The committee has not publicly confirmed Thursday's witnesses. The identities of the witnesses were first reported by CNN.

Pottinger is described as a "straight shooter," "serious professional," and a NSC staffer with deep experience on China, a close associate said, CBS News senior investigative correspondent Catherine Herridge reports. The close associate said Pottinger was "horrified" by what he saw on Jan. 6, which prompted his immediate resignation.

Charles Kupperman, former deputy national security adviser, told to CBS News he expects Pottinger's testimony on Thursday to paint a chaotic picture in the West Wing.

On Jan. 6, Kupperman reached out to Pottinger after he learned that Washington, D.C. Mayor Muriel Bowser was struggling to reach the White House about the status of the National Guard and whether the order to deploy had been given. Kupperman said Pottinger went to White House chief of staff Mark Meadows, who apparently thought the order had been given to deploy the guard and protect the Capitol.

Kupperman expects his conversation with Pottinger on Jan. 6 to be central to Thursday testimony, Herridge reports.

Catherine Herridge contributed to this report.