WASHINGTON — Andy Marshall, who ran the Pentagon’s Office of Net Assessment for more than 40 years, has died at the age of 97.

The news was announced at a House Armed Services Committee hearing by ranking member Rep. Mac Thornberry, R-Texas, who cited Marshall as a driver of new game-changing technologies and a thought leader in handling great power competition.

“I can think of fewer people who have had a bigger impact of focusing our defense efforts, our national security, in the right direction than Mr. Marshall,” Thornberry said. “He has been before our committee I don’t know how many times over the years. So I wanted to note that passing, but also to honor his memory because he made such a difference.”

The Office of Net Assessment is an independent organization within the Defense Department. It’s charged with identifying emerging or future threats as well as opportunities for the U.S. James Baker has run the office since 2015, when Marshall retired at the age of 93.

Known as farsighted, idiosyncratic, and free of political and bureaucratic thinking, Marshall made the office into an extension of himself. He was credited with grooming some of Washington’s leading thinkers, such as Gen. Paul Selva, the vice chairman of the Joint Chiefs of Staff, and a large number of defense analysts in the think tank community.

An expert on nuclear strategy with the think tank Rand, Marshall was brought into the Pentagon during the Nixon administration to provide deep, long-term planning assessments about ways to impose costs on potential foreign competitors.

Allegedly seen by Chinese defense officials as a great strategic thinker and nicknamed the “Yoda” of the Pentagon, the legend of Marshall was canonized in 2015 with the publication of “The Last Warrior: Andrew Marshall and the Shaping of Modern American Defense Strategy,” by Andrew Krepinevich and Barry Watts.

At the time of Marshall’s retirement, Defense News wrote: “No single individual has had a greater, nor more sustained, effect on U.S. national security, whether through his work to ensure success during the Cold War, or the decades after by consistently finding ways to impose strategic costs on America’s adversaries.”