Good question, my dad was a US official and we used to discuss such matter on occasion.
It has failed and become a place for extreme liberal thinkers and thirdworld countries to stand on a platform and badmouth the United States, using our money since we've always paid most of the cost for the running of that organization.
Being formed after WW11 it was intended to ensure that other world wars would not take place, help advance smaller countries and Help, and I stress Help, them help themselves, not demand that bigger, more advanced countries like ours give them what we worked so hard for while they just put their hands out and demand to be given what they haven't earned. My dad felt that it not only outlived it's usefullness but has become counter productive and in some ways a threat to the US and other democratic countries. It also serves as a place for extremist, like Iran, etc. to take popshots at the US and our allies. Kind of like so many extreme liberal special interest groups do in this country using the liberal news media and Hollywood. Just conveying some of the comments my dad used to say, and I now find to be true.