system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: What would happen if the United States left the United Nations?
gpt
The US would be the one to lose legitimacy. Any military action undertaken by the US without UN sanction would potentially be an act of war. A number of international treaties and agreements would be voided. The US would have no official means of input on international peace keeping, aid or embargoes. It would legitimize Islamic criticism of the US as being prone to unilateral action and they would no longer have a veto which would leave Israel very exposed.  It would be very bad for the US and the UN.