Confirmation ends longest period in Pentagon history without a congressionally approved leader.

The Senate voted to confirm former Raytheon Co. executive Mark Esper as U.S. defense secretary, ending the longest period in Pentagon history without a congressionally approved leader. Mr. Esper was confirmed by a bipartisan tally of 90 to 8, with all of the “no” votes coming from Democrats. None of the six senators running for the 2020 Democratic presidential nomination supported Mr. Esper, with five voting against the nominee, and one, Sen. Bernie Sanders (I., Vt.), not voting.

Like Mr. Mattis, Mr. Esper, 55 years old, is a military veteran. He was a West Point classmate of Secretary of State Mike Pompeo and served in the Army and the National Guard. He made his career, however, as a lobbyist for defense giant Raytheon and as a policy adviser in various roles on Capitol Hill and at the Pentagon. Mr. Esper takes over as the Pentagon tackles a range of internal challenges and threats around the world. He will inherit a department that is attempting to pivot from a focus on asymmetrical warfare with militant groups such as Islamic State to maintaining U.S. strength in the face of military buildups by China and Russia.

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