The US is a massive trading partner for most countries and has a strong economy backed by the American consumer. Not to mention defence and liquidity funding relationships (backed by world reserve currency). No leader is willing to cut themselves off from that.
Discussion
No one leader, maybe. But if they all get together they can and will. Remember: they have literally all the other countries in the world to trade with. If they all decide to stop trading with the US to teach us a lesson we'd be screwed and cave in real fast. American arrogance and overconfidence can cost us dearly.