Jim Mattis is not lonely in the Pentagon, but two months into his tenure as secretary of defense not a single political appointee has joined him.

The retired Marine general, who took office just hours after President Donald Trump was sworn in, has sparred with the White House over choices for high-priority civilian positions that, while rarely visible to the public, are key to developing and implementing defense policy at home and abroad.

When the Obama administration closed shop in January, only one of its top-tier Pentagon political appointees stayed in place — Robert Work, the deputy defense secretary. He agreed to remain until his successor is sworn in. So far no nominee for deputy has been announced, let alone confirmed by the Senate.

The administration has announced four nominees for senior Pentagon civilian jobs, and two of those later withdrew. Trump’s nominee to lead the Army, Vincent Viola, withdrew in early February because of financial entanglements, and about three weeks later Philip B. Bilden, the Navy secretary nominee, withdrew for similar reasons.

On Tuesday, the White House announced it intends to nominate John J. Sullivan to be the Pentagon’s chief lawyer. In January, Trump announced former congresswoman Heather Wilson of New Mexico as his nominee to be Air Force secretary, but he has not submitted the nomination to the Senate.