It moreso comes from his ability to leverage the near unlimited power of the presidency against his perceived enemies. When he says this kind of shit out loud, hes sending mob-like warnings. Go along with my narrative, or else Ill sue, tariff, arrest, annex, bomb, etc to get my way.  He doesnt have to engage in actual diplomacy because he knows hes the biggest bully of the strongest country in the world and just the implied threats should be enough to get others to fall in line.