The costs of war and containment
Three economists at the University of Chicago business school, Steven Davis, Robert Topel, and Kevin Murphy, have a short paper (in pdf format) making a comparison of the cost of war versus containment, in terms of costs to the US, to Iraq, and in Iraqi lives lost. In every category, war is the better option by several orders of magnitude.
UPDATE: Dan Drezner weighs in on this too. To emphasize a point that already has one comment that is misunderstanding the issue, costs are the sacrifices that are made. Lost lives are a sacrifice (and therefore a cost), and it is useful to ask how many lives (and possibly whose) are lost under war and under containment.