It's definitely the implicit threat behind trump's intimidation tactics but if it does come to that it won't be the duty of countries to keep him satiated just enough. It will be to send evil Americans home to their families in coffins if Trump sends them across borders.If leaders throughout the world stonewall Trump (sans Russia) he will use the military to take what he wants. This is a dangerous game to play, pushing a narcissistic authoritarian to the edge. They can't 100% appease him, but I'd be warry of spitting in his face. Trump will go to war with Mexico if he's pushed hard enough.