Bush talked about doing this, it's an end run around the U.N.. He didn't put it exactly like this but the meaning was clear. Since the U.N. is a failure, the U.S. will form another organization, now it has.
The bottom line, however well intended, is just another entaglement on the road to the united states of the western hemisphere. The West's answer to the E.U. Both are bad ideas.
Jed Babbin Talks about this in his new book
"Inside the Asylum"
why the united nations and old europe are worse than you think.
(note, VERY good book)
This was the first I've heard about it.