Opinion: The January 6 hearing witness who should make Trump nervous, CNN.com

"Peter Bergen is CNN's national security analyst, a vice president at New America and a professor of practice at Arizona State University. Bergen's new paperback is "The Cost of Chaos: The Trump Administration and the World." The views expressed in this commentary are his own. View more opinion on CNN." (CNN)Matthew Pottinger is one of the very few senior officials to have served for almost the entirety of the Trump administration. He only submitted his resignation on the day of the US Capitol riot -- January 6, 2021. Pottinger is expected to be a star witness at Thursday's climactic final summer public hearing of the House select committee investigating the attack on the US Capitol. As the deputy national security adviser when the insurrection happened, Pottinger is the most senior Trump administration official to testify before the committee publicly. His words are likely to carry a lot of weight. Throughout each step of his career, Pottinger, now in his late 40s, has shown a marked streak of independence and fortitude. It will be difficult for Team Trump to paint Pottinger as a junior official who wasn't "in the room" for the events that he will testify about, or that he is part of the purported "deep state" -- since he was appointed to the administration by Trump's first national security adviser, retired Lt. General Michael Flynn, who has since been at the forefront of the efforts to overturn President Joe Biden's electoral victory. Pottinger's long service in the upper echelons of the Trump administration is why committee members saved him for what they must be hoping will be a dramatic prime time moment on Thursday. (Disclosure: I was interviewed by staff members of the committee who were interested in discussing the history of right-wing terrorism). Pottinger is also far from a typical Trump apparatchik, nor is he a typical civil servant. He has had a very varied career from working as a reporter in China for the Wall Street Journal; to serving as an officer in the US Marines in Afghanistan; to working at an investment fund in New York before he served as a top national security official at the White House. Pottinger's father, John Stanley Pottinger, was a lawyer in the civil rights division of the Richard Nixon and Gerald Ford administrations. He was educated at the Massachusetts prep school Milton Academy and then at the University of Massachusetts where he studied Chinese. Pottinger is now married to the medical researcher and virologist Yen Pottinger, who fled Vietnam as an infant. As a reporter in China, Pottinger faced down threats from the Chinese security services, as he recounted in a 2005 essay in the Wall Street Journal. "I've been arrested and forced to flush my notes down a toilet to keep the police from getting them, and I've been punched in the face in a Beijing Starbucks by a government goon who was trying to keep me from investigating a Chinese company's sale of nuclear fuel to other countries," he wrote. After his posting in China, Pottinger took the unusual step for a journalist of joining the US Marines in 2005 at the relatively late age of 32. The Marines then deployed him to Afghanistan and Iraq. It was in Afghanistan that he crossed paths with then-Major General Michael Flynn. Together they co-authored an influential paper "Fixing Intel," which made the case that US intelligence agencies officials had to do a better job of getting out among the Afghan population if they really wanted to understand what was going on in Afghanistan. The paper's publication in 2010 caused a stir, as it was published outside of regular government channels by a Washington DC-based think tank. In 2017, after Flynn was appointed Trump's first national security adviser, he tapped Pottinger to be the top official on Asia policy at the White House. Pottinger's years working as a reporter in China proved to be quite consequential for the Trump administration, as his experiences there deeply informed his skeptical attitude to the Chinese and were subsequently reflected in the Trump administration's policies on China. Those experiences also colored Pottinger's perception of the threat posed by a mysterious new disease originating in China known as Covid-19. Flynn served only three weeks as national security adviser before he was fired because he had lied to then-Vice President Mike Pence about the content of his discussions with the Russian ambassador to the United States. r Flynn's successor as national security adviser, Lt. General H.R. McMaster, relied on the Mandarin-speaking Pottinger and his deep expertise on China. In McMaster's book "Battlegrounds," which recounts his work at the Trump White House, he describes Pottinger as "my 'professor'" on China. The fruits of McMaster and Pottinger's work on China could be seen in the Trump administration's national security strategy, released in 2017, which took a far more skeptical and hardline approach to China than previous administrations had. The Trump strategy accused the Chinese of stealing US intellectual property every year valued at "hundreds of billions of dollars" and warned that China "is building the most capable and well-funded military in the world, after our own." When Covid-19 first emerged as a public health issue in early 2020, Pottinger -- who had covered the SARS outbreak in China when he was a reporter -- took the possibility of the emergence of a pandemic far more seriously than most Trump officials did. Trump himself was largely dismissive of the threat and denigrated mask-wearing, which was one of the only effective public health measures before vaccines against Covid-19 became available. According to Pulitzer Prize-winner Lawrence Wright's authoritative book about the Trump administration's response to Covid-19, "The Plague Year," Pottinger bucked the prevailing winds at the Trump White House, wearing a mask to meetings beginning in March 2020 when no other Trump officials were wearing masks. He was also instrumental in persuading Trump to close down most travel from China to the US in the early days of the pandemic, according to Wright. Pottinger persuaded leading American public health expert, Dr. Deborah Birx, to come to the White House to coordinate the coronavirus task force that was overseeing the response to the virus, according to Birx in her memoir "Silent Invasion." On Thursday, Pottinger, who has stayed largely out of the spotlight during his career, will step forward into what will surely be the most well-publicized role of his life, as a witness to what his commander-in-chief was doing during the assault on the US Capitol. That role will be informed by Pottinger's career as a journalist reporting under difficult circumstances in China, as a US Marine officer serving at the height of the Afghan War and as an official who survived almost four years in the tempestuous Trump White House. It will be the role of a lifetime. And I anticipate his testimony will be both highly credible and quite damaging to Trump and his gross dereliction of duty while his supporters swarmed and attacked the Capitol.