The issue is a different one. Even if we all agree on the justification behind retaliation (a very popular word here in the US for the past 4 months), what do you do when you have no enemy to fight against? Bush seems to have directed his war efforts toward terror funders/protectors/etc since he could not fight the REAL enemy (200 guys in the middle of the Afghani desert). Gilad is correct in his reply - the American people needed a villain, and needed to feel that they have the ability to fight back. Anti-war criticism here (US media) is very rare and is being pushed away from mainstream journalism.
On the other hand, who are we to judge them, with "retaliation" being our bread and butter for years now...