But it is a huge intellectual leap to go from saying garbage should be collected to saying that the government should collect it. Similarly, you need to demonstrate that the United Nations' noble efforts cannot be carried out by someone else.
More to the point, it's an even grosser intellectual stolen base to claim or suggest that because the United Nations does good things in Somalia or Sri Lanka that we should assume its political motives are just as pure. The Nazis were brilliant at delivering social services. Hamas' "political wing" builds hospitals and inoculates babies, but that doesn't make it any less of a terrorist organization.
Now, the United Nations isn't a hotbed of Nazis and terrorists, by any stretch. But it's not a democratic, representative body either. Absolute power resides in the Security Council, whose core members originally included two brutal totalitarian regimes, China and the Soviet Union - both of which remain (in altered form) authoritarian regimes to varying degrees. Meanwhile, the larger General Assembly is chockablock with kleptocratic lickspittles working on orders from their dictatorial paymasters in Asia, Africa and the Middle East.
This is why I find it so infuriating when people talk about how the "nations of the world" voted on this or that in some U.N. resolution. No they didn't. Some nations voted through their representatives, other nations had one criminal cabal or another vote in their name. And if you believe - as so many opponents of the Iraq war did - that barbaric dictators are legitimate rulers because international law says so, then international law upholds the logic of the Fuehrer.
As for the other argument - that America needs the United Nations to check and thwart its ambitions - I have even less patience. Usually such arguments are made by non-Americans who fear or hate the United States (France, call your office). Right or wrong, it's perfectly legitimate for foreigners to make this case. Germany defines its interests differently than America does. But when Americans make this argument, my eyes roll. Yes, you can think it's in America's interest to have bureaucratic Lilliputians from the "international community" tying America down and giving a megaphone to our enemies. But that strikes me as an odious case for an odious institution.