Mr. Gates, who was appointed defense secretary by President George W. Bush and kept on by President Barack Obama, said the killing of George Floyd in police custody in Minneapolis had focused new light on a legacy of racism that should be confronted in society, including within a military that is increasingly diverse.

“The events since the killing of George Floyd present us with an opportunity where we can move forward to change those bases,” Mr. Gates said in an interview. “It’s always puzzled me that we don’t have a Fort George Washington or a Fort Ulysses S. Grant or a Fort Patton or a facility named for an African-American Medal of Honor recipient. I think the time has come, and we have a real opportunity here.”

As a longtime Soviet scholar, he added, “I’m very sensitive to the notion of rewriting history.” But he said base names and statues of Confederate figures should not be seen as honoring them. “They belong in a museum someplace so we’re not celebrating them, we’re learning from them and the mistakes they made,” he said.