Has the US broken the UN Charter by resuming hostilities with Iraq?

Considering the actions by the US and the legal position outlined in this thread.

Has the US broken the UN Charter in by resuming hostilities with Iraq?

No the US has not broken the treaty as the Iraq conflict was under ceasefire.

Iraq broke several of the conditions that bound the ceasefire. WMD was not required in a legal sense to resume hostilities, they where needed to drum up pub(l)ic opinion.