As to the subject at hand, I have a tiny bit of insight. This was job #1 when the Bush administration came in. (Recall how early in the game Negroponte was nominated, though the foot-dragging by liberals slowed that down a bit.) In part, because it was immediately faced with the Durbin conference that was designed to be an Israel-bash-fest. Immediately after that we would have to deal with the "rights of the child" issues and so much more. The new administration first cleaned out old Clinton staff holdovers here AND they began developing policy groups of conservative scholars and experts to send to conferences. Those libs they couldn't get rid of fast enough were simply left out of the loop and neutralized. (It's a bit easier to rearrange things in this area because you aren't dealing with as many career government workers, unlike over at DOJ and the Pentagon.)
The U.N. situation is a vital part of U.S. foreign policy and the President wants his people there to influence the process, though (unlike his father) he is an isolationist at heart. It's tough to be the latter in a world where acting on those inclinations would be unrealistic and have tragic results on all fronts.
As to the earlier question of what is the U.S. policy? Pro-life, pro-traditional-family, pro-sovereignty. Anti-redefining family, anti-exporting abortion around the world, and anti-international courts/jurisdictions/investigations/intrusions/etc. None of this will be easy to accomplish, but we have the right man in office to hold the U.N. at bay. After all, when was the last time we had a president completely withdraw from a U.N. convention when the tone was unacceptable going in? Never.