The day after President Donald Trump announced, contrary to the advice of military and civilian advisers, that the United States would withdraw all troops immediately from Syria, Defense Secretary Jim Mattis announced his "retirement" - or, in the vernacular, that he was quitting. His resignation letter included a not-so-subtle rebuke of Trump. He wrote:
"One core belief I have always held is that our strength as a nation is inextricably linked to the strength of our unique and comprehensive system of alliances and partnerships.
"While the U.S. remains the indispensable nation in the free world, we cannot protect our interests or serve that role effectively without maintaining strong alliances and showing respect to those allies.