You had me agreeing up till that point. The UN is not in our best interests, "improved" or not. We should not be subjecting our decisions to review by foreign governments at all.
Well, we have to look at the same question I asked BE: what, exactly, IS "the national interest?"
In the current situation, for example, it may be in OUR interests that UN troops are sent to Sudan (or Congo.) Both countries are run by slimebag despots who are wholesale eliminating parts of their population.
BUT--there are not a whole lotta US troops to spare.