If Tony Blair did not think that he needed a second UN Security Council resolution for permission to invade Iraq, then why did he first set out to get one?
As Robin Cook said in his resignation speech:
"I applaud the heroic efforts that the Prime Minister has made in trying to secure a second resolution. I do not think that anybody could have done better than the Foreign Secretary in working to get support for a second resolution within the Security Council. But the very intensity of those attempts underlines how important it was to succeed. Now that those attempts have failed, we cannot pretend that getting a second resolution was of no importance."
Blair cannot go with the law when it suits him and then go against it when it does not. He knew going to war was against the law and he should be tried at the Hague.