This is a link to the War Powers Act passed by Congress in 1973:
http://www.cs.indiana.edu/statecraft/warpow.html
This is a link to the Declaration of National Emergency lawfully invoked by President Bush on 9/14/01:
http://www.whitehouse.gov/news/relea...0010914-4.html
Below is the authorization of use of military force passed by congress:
http://thomas.loc.gov/cgi-bin/query/.../~c107buVENZ::
Here is an excerpt from the above of which I have marked two significant phrases in bold:
"(a) IN GENERAL- That the President is authorized to use all necessary and appropriate force against those nations, organizations, or persons
he determines planned, authorized, committed, or aided the terrorist attacks that occurred on September 11, 2001, or harbored such organizations or persons, in order to
prevent any future acts of international terrorism against the United States by such nations, organizations or persons."
On a side note paragraph (c) of the following link is particularly interesting:
http://www4.law.cornell.edu/uscode/50/1541.html
It is my opinion that the current President of the USA has the required authority to send troops to Iraq and conduct warfare as
he deems fit so long as he consults with Congress on a regular basis as specified in the War Powers Act of 1973.
Some of us may disagree on whether or not it is wise for the US to go to war in Iraq, but insofar as to whether or not the President is lawfully able to make this decision should not be in dispute.