Obama nominates Ashton Carter to be defense secretary

President Obama formally nominated Ashton Carter to be his fourth defense secretary Friday morning.

Mr. Obama hailed Carter as "one of our nation's foremost security leaders" and said Carter would bring to the job a unique combination of "strategic perspective and technical know-how."

If confirmed by the Senate, Carter will replace outgoing Defense Secretary Chuck Hagel, who resigned last month.

"I accepted the president's offer to be nominated for secretary of defense because of my regard for his leadership," Carter said. "I accepted it because of the seriousness of the strategic challenges we face, but also the bright opportunities that exist for America if we can come together to grab hold of them."

Carter said to Mr. Obama, "I pledge to you my most candid strategic advice [and] equally candid military advice."

Carter was deputy secretary of defense between 2011 and 2013, serving as the Pentagon's chief operating officer under both Hagel and Hagel's predecessor, Leon Panetta. Before that, he'd served in a variety of roles within the Pentagon under Mr. Obama and former President Bill Clinton. Carter, who holds a doctorate in physics, has also been on the faculty at Harvard and MIT, and is currently a lecturer at Stanford.

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As the number two at the Pentagon, Carter helped oversee the department's budget during a period of belt-tightening, and he boasts a deep familiarity with the department and its massive bureaucracy. He stepped down in 2013 after Mr. Obama passed over him to nominate Hagel when Panetta retired.

Carter is viewed favorably in defense circles, respected by senior military leaders and well-known within the Pentagon civilian bureaucracy. Carter is also seen within the White House as an upgrade over Hagel in terms of strength of personality, confidence and vision on current national security challenges in the Middle East -- specifically coalition efforts to defeat the Islamic State of Iraq and Syria (ISIS).

"He's a reformer who's never been afraid to cancel old or inefficient weapons programs," Mr. Obama said. Additionally, he's "known by our friends and allies around the world [and] respected and trusted on both sides of the aisle."

Mr. Obama also praised Carter's "true regard, his love for the men and women in uniform, his relentless dedication to their safety and well-being."

Carter, if confirmed, will take the the helm of the Pentagon as it is facing multiple crises abroad, ranging from the rapid rise of ISIS to ongoing international talks to curb Iran's nuclear program and the spread of Ebola in West Africa. Additionally, Mr. Obama has quietly moved to expand the U.S. military role in Afghanistan in 2015.

Carter's first challenge will be surviving the Senate confirmation process. After the new Republican-led Senate is sworn in next year, it will have to consider the nominations of both Carter and Loretta Lynch, Mr. Obama's nominee for attorney general. Should the new GOP leadership keep the current Senate rules, Mr. Obama's nominees will need the support of a simple 51-vote majority to be confirmed. Still, the confirmation votes set the stage for early political tension between Mr. Obama and the new GOP Congress.