President Donald Trump says the quiet part out loud. He has no sotto voce setting. This militates against statesmanship. 

Former President Bill Clinton told CNN years ago it’s best to be “brutally” honest in private but, if you want someone’s help, not to say things in public that embarrass them. But Trump doesn’t work that way. He is brutal in public to foreign powers and allies and trade partners with whom he is trying to make a deal.