The second war of Iraq was merely the finale of the first war in Iraq, when George Bush Sr, stopped Iraq's forces from invading Kuwait, George Bush JR decided to attack Iraq again and topple the regime entirely based on his fathers legacy. When you consider the message sent from there it shows that the United States does not forget past misgrievances.
No, the war in Irag was not worth it. I believe that most of the people in Iraq do not want our military presence, and it has not sent a message to any other countries that are under siege by their own people. There are still riots all over the world. Egypt and Syria lost many lives during uprisings. Countries run by dictators are worse than ever. People are forcing the dictators out of power only to replace their rule with brutal militia. It seems as if nobody is safe. The war in Iraq has not accomplished sending a message to rogue regimes.