The US is in a lose-lose situation with regard to the UN. Whether everything that goes on in the UN is corrupt or not can be debated, much the same as whether much of what goes on in the US is corrupt, but the heart of the issue deals with ego. Since the UN "represents" the countries of the world, whenever the US or any country turns their back on the UN, it makes it appear as if the US is turning its back to the world, which if that IS the case, can only end in the turmoil and tragedy.
Take care all.