That's just it, we as a country never declared war. Bush went to war under resolutions. I highly recommend a read of this article "Is Bush's War Illegal? Let Us Count the Ways" by Francis Boyle, a professor of international law at the University of Illinois College of Law. http://www.counterpunch.org/boyle0917.html
Excerpt:
The United States needs a new law requiring that the president consult with Congress before going to war, a blue-ribbon panel led by two former secretaries of state said Tuesday. James Baker, left, and Warren Christopher led a panel that recommended a new War Powers Act.
The current War Powers Resolution is "ineffective, and it should be repealed and it should be replaced," James Baker said in a joint appearance with Warren Christopher, announcing the results of the study they led.