With the way China and Russia are acting, the US needs more spies not less. Consider how easy it was for the US to send spies into Iraq by attaching them to the UN, ostensibly to look for NBC, but in truth to verify that Iraq didn't have WMD. Last thing the US wanted was to send troops into Iraq when we didn't know whether or not they'd be met with a mushroom cloud, or anthrax or whatever.
When things go to crap in Afghanistan, and the terrorists get active again, the UN is the perfect tool for the US to use to gather intelligence. Same with every other third-world crap hole. We can monitor what's going on anywhere in the world by sending in a few spooks under the aegis of the UN. When you consider what the US spends on the CIA, spy satellites, .etc, what we spend on the UN is a drop in the bucket. And have no doubt, the US OWNS the UN. Best worldwide spy network in history, and the US can use it anyway we want to, whenever we want to.
The people at the UN HAVE to criticize the US to make it look like the organization isn't controlled by the US, when the facts are that the US OWNS the UN and we can make it do whatever we want it to. .
Now that the CIA has shown many times that, operationally, it can't find its tookus with both hands and a hunting dog, we'd be nuts to shut down the UN.