"As you said a non-pre-emptive response to an attack that can be traced to another country, similar to the Afghanistan situation, will always be an option/possibility.

I believe it will be very difficult to get congressional and public support for a pre-emptive attack on another country for the foreseeable future. The evidence will need to be unquestionable and if it were that strong most of the western world would also sign on.

I do not believe there was deliberate deception on the WMD but there were obviously some intelligence failures that are at least a little bit embarrassing and the failures will be a topic of conversation for years, particularly when the subject of a pre-emptive strike is raised."

You seem to be implying that we were at peace with a Iraq and then we started a war with Iraq.
I have a hard time understanding why some people assume we were at peace with Iraq- we were imposing sanctions, we were flying over their terrority, we were supporting the Kurds- which ended up becoming "semi-autonomous" because we were seriously hindering any Iraq effort to "suppress this revolt". Meanwhile, Iraq was engaging in hostile acts against our "No fly Zone" planes, they had not returned all prisoners or remains from Gulf war I. It's leader was saying Iraq was at war with the US, and it's seems likely the Iraq remime attempted to assassinate a former US president (the commander-in-cheif of war he lost [though Saddam claimed to have won]). And basically Iraq since '91 had failed to comply with ANY of cease-fire agreements, nor showed any intentions of desiring to do so.
Now, when a country bombs another country- it's usually a "no brainer" that the country which is bombing is at war with the country it's bombing. Therefore, when Clinton bombed Iraq in '98, the only legal conclusion was that the US was definitely at war with Iraq.
Now, if instead of invading, Bush had pounded the "sh%t" out of Iraq with missiles and bombs, would that had been different, would these same people call this a pre-emptive strike or is it only when ground troops are used that it's called a pre-emptive strike?
I fail to see the difference other than using ground troops is more effective- and generally speaking, there is higher risks to the US combat troops.