The UN is used as a tool by the US when it ONLY suites its interests PERIOD. If it doesn't suite its interests, it holds the veto card where it really matters. Therefore you are correct that it's useless because if applied correctly, the INTERNATIONAL COMMUNITY should outweigh the USA in all int'l matters. Also to your point, last I checked Iran, Syria, etc do NOT have veto power so you are again wrong in your assessment.
Man shot dead in northern Israel town of Bi'ina, police say the murder was gang related (Haaretz)