Leon...I think you over-simplify the possible outcomes here. There are more than the two you suggest:
1) a peaceful resolution...bullish 2) a quick war (1-3 weeks) with initial impacts yielding positive results for the US...bullish 3) a complicated, drawn out (months) urban war after initial results leaving no clear progress...bearish 4) continued delay tactics by Saddam that are tolerated by the UN and prevent a solution before the summer...bearish 5) a WMD strike by Saddam...bearish
...and there may be even more that I haven't considered. There is a great deal of uncertainty, make no mistake about it.