The coalition of the willing didn't have the UNs approval when they went in to Iraq. They got it retroactively.
http://en.wikipedia.org/wiki/United_Nations_Security_Council...
On September 16, 2004 Secretary-General of the United Nations Kofi Annan, speaking on the invasion, said, "I have indicated it was not in conformity with the UN Charter. From our point of view, from the charter point of view, it was illegal."[1]