In legal terms, "assault" is defined (from the Merriam-Webster dictionary as:

assault

Etymology: Middle English assaut, from Old French, from (assumed) Vulgar Latin assaltus, from assalire
Date: 14th century
1 a : a violent physical or verbal attack b : a military attack usually involving direct combat with enemy forces c : a concerted effort (as to reach a goal or defeat an adversary)

2 a : a threat or attempt to inflict offensive physical contact or bodily harm on a person (as by lifting a fist in a threatening manner) that puts the person in immediate danger of or in apprehension of such harm or contact -- compare BATTERY 1b b : RAPE

So, if you see someone "lifting a fist in a threatening manner", you're under assault and have the right to protect yourself. That may involve blocking the punch or even throwing one first if that's what's necessary to protect yourself.

Now, when it comes to "incontroverible evidence of imminent attack", that happens more often in the movies than in real life. Just a couple weeks ago, you were lambasting the Bush administration for not taking actions to stop the 9-11 attacks based on the sketchy evidence available at the time. Obviously, there were some major intelligence failures in the years leading up to the attack. It's kind of funny that you then take the word of the same intelligence agencies when it suits your argument that there is no evidence that Saddam has anything to do with WMD. It sounds like you're cherry-picking your sources when it suits you rather than trying to find the truth.

As to whether Saddam has WMD or not, there are differing opinions. Much has been made of what former weapons inspector Scott Ridder as said in recent weeks. Less has been mentioned about what other weapons inspectors have said, such as Richard Spertzel (United Nations' chief biological weapons inspector in Iraq from 1994 to 1998 - Ridder's boss).