Why Obama's New Defense Nominee Likes 'Charmed Quarks'

The man President Obama has tapped to be his next Secretary of Defense is an expert in "charmed quarks."

Ashton Carter is a physicist and medieval historian by training, educated at Yale and Oxford and teaching classes at Harvard, according to his official biography. In 1975, he published an article in Yale Scientific titled "Quarks, Charm and the Psi Particle."

"I liked dusty archives, learning to decipher manuscripts in medieval script, and learning all the languages necessary to read the primary and secondary historical literature, especially Latin," Carter, a Yale double-major, wrote in a 2007 autobiographical essay posted on his Harvard faculty page. "Physics was entirely different: clean and modern, logical and mathematical."

It's that tendency toward the orderly and efficient that made Carter, 60, a valued Defense Department adviser during stints in the Clinton and Obama administrations, according to public accounts by former colleagues. He lent expertise to strategic nuclear weapons policy and, more recently, to management of military technology and logistics.

His intellectual chops have won the former Defense deputy secretary praise from inside the Pentagon and from members of both political parties in Washington, D.C.

"He's not controversial," Sen. John McCain, R-Ariz., told ABC News. "He's qualified and he's the last man standing."

Republican Sen. Jim Inhofe of Oklahoma said he is "pleased" with the Carter pick. "I can't imagine that he's going to have opposition to his confirmation," he told The Associated Press.

Sen. Carl Levin, the outgoing Democratic chairman of the Armed Services Committee, told ABC News that Carter was "highly qualified."

While indications from Capitol Hill suggest the Philadelphia native will be confirmed, his confirmation hearings are likely to become a lightning rod for criticism of Obama's foreign policy.

"All decision making is amongst a handful of people in the White House who only have one thing in common, that they don't know anything about the military," McCain said.

Carter himself has openly reflected about the challenges of working within the executive branch bureaucracy. In his 2007 faculty autobiographical essay, he wrote that serving at the Pentagon can be onerous because of the "many bosses."

"Public service at senior levels in Washington is a little bit like being a Christian in the Coliseum. You never know when they are going to release the lions and have you torn apart for the amusement of onlookers," Carter wrote. "And then, of course, if your job is world affairs, reality intrudes even in Washington. Crises and emergencies and conflicts erupt around the world on their schedule, not yours."

A Secretary Carter would face a number of still-erupting crises upon taking office, from the fight against ISIS militants in Iraq and Syria, to Russian incursions into Ukraine, an active war in Afghanistan and pressing concerns about budget and sexual assaults within the ranks.

ABC's Jeff Zeleny contributed reporting.