Get 'er done.
I think we should withhold all the money, and tell the UN, "don't call us, we'll call you" and see how long they last without our $$$$. I think the US and Japan provide about half of their funds. I bet it wouldn't be too hard to convince Japan to follow us in withholding the money.
Why are we paying them to thwart us, every time we try to do something good in the world?