By losing their job?
Bush paid a high political price for the failure post invasion of Iraq. Namely the 2006 mid terms and the wash out of republicans in 2008. But Bush didn't violate every premise of American foreign policy:
1. He had intel that Saddam had WMD - from State, CIA, and foreign sources.
2. He had UN approval for use of force.
3. He went to congress and got approval for use of force.
4. Saddam was in repeated violation of the truce we signed with Iraq to end Op Des Storm.
5. Saddam was given multiple chances to peacefully abide by the treaty and refused.
I agree it was botched post invasion, and even parts of the invasion. In retrospect, I'm OK with the reaction given what was known, but consider Bush responsible for the failure to secure a peace that maximized American interests.
Going further down this would be a side track - I only respond because you are acting like I'm a fool for caring about Libya, when I didn't care about Iraq, which of course I did and do. BTW Bush isn't in office and we don't have the Delorian from back to the future, and the Bush/Patreus surge quieted things long enough to allow for BHO to declare victory and pull out troops - so there is no possible way to effect that situation OR risk that Bush would repeat it.
On the other hand Obama went into Libya without any reason, half heartedly led from behind, failed to secure ANY kind of peace and resulted in a NET change that weakens American security AND prestige. WITHOUT Congressional authorization. Ever.
That is the fundamental American philosophy of military control: military serves the civilian gov't, congress declares war - executive executes it. The fundamentals of American Foreign policy are not static - so your claim that Bush violated them is absurd: Manifest destiny, the Monroe Doctrine, the FDR get involved every where doctrine, the containment doctrine, the end of history doctrine? Laughable - every admin brings its own philosophy of foreign affairs and can and should be judged. Obama's doesn't look very different from Bush's. We're fighting 6 or 7 active conflicts right now. Media just doesn't care.