Allowances

"But what if ...?" And here come the hypotheticals (which aren't really necessary since the world is full of actuals) positing all the many scenarios in which it is not only acceptable, but obligatory, to take some action that will, in fact, result in civilians getting killed.

The common thread in all of these scenarios -- hypothetical or actual -- is the idea of double effect....

That's what separates an army from a barbarian horde. That's what separates a soldier from a thug with a gun.

The key elements here are the intent, the justice/goodness and necessity of the primary effect, and the inescapable/unavoidable nature of the secondary, unintended effect. All of which sets the bar considerably higher than the oversimplified cartoon version of "the ends justifies the means."

If there is any possible way to achieve the intended effect without producing the unintended effect, then double-effect does not apply -- the doctor may not slice, the general may not attack. If there is any possible way to achieve the necessary intended effect without producing the unintended effect and you act, instead, in a way that produces this secondary effect, then you have not produced "collateral damage," you have simply slaughtered civilians.

[via slacktivist]