When is it ok to use the troops?

Ace says:

It is strange, but here's how liberals think:

If there is a strategic advantage to America taking military action against a corrupt and murderous regime, we must not do so. The mission may be justifiable on moral grounds, but the possibility that America herself will gain from taking the action taints it too much to even comtemplate.

Meanwhile, if there is absolutely no possible selfish national-security benefit to be gained for America, the left is pretty comfortable with putting our soldiers in harm's way. Haiti, Bosnia, Dafur. Each of these presents a strong case for intervention on moral grounds alone-- without any appreciable strategic benefit to America. As there is no chance that America may benefit from such interventions, the left supports risking our soldiers' lives and limbs to intervene.

They're so fearful of Enemy America that they would rather innocents suffer than so much as risk America gaining in some way from a use of force.