As I've been suggesting, a war with Iraq is merely preliminary to what will turn out to be a much more difficult war against the shadowy terrorist groups. Right now, Iraq is stronger militarily than those groups, but Iraq is vulnerable to U.S. military might. The terrorist groups are currently less of a threat, but they are much more difficult to fight, and they will be getting stronger.
I believe that it does make sense to tackle Iraq now, both because of the semi-traditional threat that it embodies (which is Pres. Bush's primary justification for the war) and because it will deprive the terrorists of some powerful state support, including a likely base of operations.
Nevertheless, this is one of the last stands of conventional warfare, rather than the true beginning of the war against Islamic terrorism.