He Was America’s Highest-Ranking Military Officer. Then Came the War on D.E.I.

During his decades-long path to become America’s highest-ranking military officer, Gen. Charles Q. Brown Jr. won the crucial support of President Trump. That all changed when Mr. Brown publicly talked about a subject that is taboo in Mr. Trump’s government. Helene Cooper, who covers national security for The Times, explains why General Brown was fired and why it has rocked the military.