John Kelly, at Center of Report on Trump Disparaging U.S. Soldiers, Keeps Silent

Mr. Kelly’s silence did not save him from the president’s wrath.

“This man was totally exhausted,” Mr. Trump said of Mr. Kelly at a news conference on Friday. “He wasn’t even able to function in the last number of months.”

In the wake of The Atlantic’s report, the pressure on Mr. Kelly has been building.

“There is nothing noble about choosing loyalty to a former boss over fidelity to his oath to support and defend a Constitution that is under siege by that same boss,” said Philippe Reines, a former top adviser to Hillary Clinton.

Mr. Reines was working for Mrs. Clinton when she was secretary of state and praised Mr. Kelly, then the senior military aide to Defense Secretary Leon E. Panetta, for swiftly finding a plane to transport the bodies of the four Americans who died in the attacks in Benghazi, Libya, from a ceremony at Joint Base Andrews to Dover Air Force Base.

Mr. Kelly was also on the advisory board of Mr. Reines’s former consulting company, Beacon Global Strategies. “If his and others’ silence is based on assuming Trump will lose without their having to speak out, well, we’ve seen that movie before,” Mr. Reines said. “If Trump is re-elected, their current silence will have played a big part.”

Friends and associates of Mr. Kelly said that his calculation about whether to speak out was also intertwined with publicly revisiting his son’s death.

“He was very private about the loss of his son, and we as his staff fully respected that,” said Elizabeth Neumann, who was deputy chief of staff to Mr. Kelly when he was secretary of the Department of Homeland Security. “This is not the type of thing he wants politicized and doesn’t feel like it’s the right thing to speak about.”

Mr. Kelly, who served three tours in Iraq during some of the worst violence there, later became chief military aide, a highly influential position, to Defense Secretary Robert M. Gates; he continued in the position under Mr. Panetta. Mr. Kelly went on to become the commander of United States Southern Command, which oversees all American military operations in Central and South America.