Late last week Army Gen. Mark Milley, the chairman of the Joint Chiefs of Staff, issued an extraordinary apology for his participation in that awful presidential photo op made possible by the use of tear gas against peaceful protesters. But as Helene Cooper noted in a story in The Times, that’s just one example of an intensifying friction between the president and military leaders. Many of them don’t share his opposition to renaming bases that honor Confederate officers and disagreed with his push to have armed forces quell demonstrations.