The man President Obama is expected to choose to be the next secretary of defense has a long history at the Pentagon, having served in senior positions there for nearly five years. But one of his specialties is particularly timely: Ashton B. Carter is considered one of the country’s top administrators and students of military technology.

Carter, an Oxford and Yale-educated physicist, served as the undersecretary of defense for acquisition, technology and logistics from April 2009 until October 2011, as the Pentagon ended its eight-year war in Iraq and surged thousands of additional troops into Afghanistan. The job required him to find ways to rush into the field new equipment that was needed by troops and to prepare for emerging national security issues, including cyber warfare and the proliferation of drones.

Carter, speaking in February 2011 at the Cowen Investment Conference in New York, said that while the Pentagon needed to rein in spending after a decade at war, it was in U.S. interests to keep the defense industry strong and encourage small tech companies to compete with corporate giants.

“Smaller firms, start-ups, and new entrants provide needed new technology, new faces, and new ideas to the defense industry,” he said. “The nation’s small businesses add vitality to our base in both prime and subcontractor roles. Mid-sized companies are especially important and worthy of fostering, as they can grow into new sources of innovation and competition.”

One interesting piece to that was shepherding partnerships between industry and the Defense Department. Some of them went through the Defense Advanced Research Projects Agency, a Pentagon organization that has played a leading role in developing high-tech programs for everything from robotic hand replacements to underwater drones.

Carter ascended to become the deputy defense secretary from October 2011 to December 2013, and continued to highlight the need for new technology in the military. In a speech at the American Enterprise Institute in May 2012, he highlighted efforts the Pentagon had pursued set up a “fast lane” to get more aerial drones and Aerostat surveillance balloons into Afghanistan.

But Carter added that more needed to be done with technology in the future, even as the Pentagon cut its budget. Obama ordered the Pentagon to make sure it advances in technology where important, Carter said, citing Special Operations, drone operations and cyber warfare as examples.

“He kept saying to us: Make sure that you don’t follow the last-in, first-out rule, that you don’t pull up the things that are most shallowly rooted – namely, your new things – because that’s the easiest thing to do,” Carter said. “I want to see that we are enhancing the capabilities that are going to be part of our future.”

Carter left the Defense Department in December 2013, after Obama bypassed him to be secretary of defense in favor of Chuck Hagel. He has served as a professor at Harvard University’s Kennedy School for Government and a lecturer and distinguished visiting fellow at Stanford University’s Hoover Institution recently.

Carter joined the Defense Department in the early 1980s, working on missile defense and nuclear weapons. As noted in this 2012 Boston Globe profile, he was probably best known in Washington until recently for having a leading role in the Pentagon’s Cooperative Threat Reduction program, which dismantled 8,000 Soviet nuclear weapons. Obama personally thanked Carter at a 20th anniversary celebration of the arms control effort in 2012.

“I especially want to acknowledge a leader who helped create it and who now helps guide it as our outstanding deputy secretary of defense — Ash Carter. So thank you, Ash, for your great work,” Obama said.