Dew-
I'm not sure I understand your argument. First you said "It would be fine if the US used its power in helping poorer countries." Now, it's not fine if the US helps poorer countries that don't hate the US. I don't think 'it' will ever be 'fine' for you, until all the US money and troops are under the control of the UN, which would not, I'm sure, be able to use them much more properly.
It would be fine with me if all the US troops just came home. But the next day, a call would come from some country begging for assistance (military or humanitarian), and the world community would sit on their hands until the US sent help.