Meanwhile, the national security adviser, John R. Bolton, and Secretary of State Mike Pompeo — who was a former West Point classmate of Mr. Esper — have largely run national security policy in the months since Mr. Mattis departed. Mr. Esper’s challenge, national security experts said, will be to work to get the Pentagon’s views represented among those strong personalities.
“The protracted period without a permanent defense secretary has created a vacuum,” Carl Tobias, a law professor at the University of Richmond, said in an email. “That situation has decreased D.O.D.’s influence on critical matters involving national security and military affairs and limited D.O.D.’s ability to affect important policymaking generally and on specific issues,” especially Iran, China and North Korea.
“The president needs the best advice, particularly on national security, from numerous perspectives, partly as a counterbalance to the apparently outsized recent influence being exercised by Pompeo, Bolton and perhaps others in the White House and Trump’s orbit,” Mr. Tobias said. He said that need “may help explain the unusually bipartisan, overwhelming confirmation vote that Esper secured.”
Indeed, Mr. Esper’s confirmation process was largely fast and smooth, reflecting lawmakers’ eagerness for stability at the Pentagon.
But during his confirmation hearing, some Democrats, including Senator Elizabeth Warren of Massachusetts, raised questions about Mr. Esper’s ties to the defense industry. Ms. Warren, who is running for president in 2020, in particular was critical of Mr. Esper’s refusal to recuse himself from all matters involving Raytheon once he becomes defense secretary. She voted against his confirmation.
In fact, five of the eight senators — all Democrats — voting against Mr. Esper are presidential aspirants in 2020: Cory Booker of New Jersey, Kirsten Gillibrand of New York, Kamala Harris of California, Amy Klobuchar of Minnesota and Ms. Warren.
Mr. Esper’s confirmation — he was to be sworn in later Tuesday — does not end the leadership void at the Pentagon, which still has no permanent deputy secretary of defense. David Norquist, Mr. Trump’s nominee for that job, is scheduled for his own Senate hearing on Wednesday.