O'Hara aka OccamsRazor has an article at SWJ linked by SWJBlog, Drone Attacks and Just War Theory (link to pdf). Its BLUF:

Final Thoughts

The principles of distinction and proportionality are integral to the premise that wars should be conducted in a limited fashion. Derived from theologians in the just war and natural law traditions, these principles have made their way into statutory law, as exemplified by Additional Protocol I of the Geneva Conventions. But what is the best way to interpret these provisions? Does one trust the ICRC guidance, or guidance provided by either hawkish or pacifistic legal scholars? This paper‟s answer was to evaluate which perspective best fit the construct of JWT. While perhaps not always the perfect answer, it is a useful guide in sorting through the various interpretations of distinction and proportionality held in international law. Now, more than ever - with the Obama administration‟s use of targeted killing so prevalent - does this dialogue about drone attacks need to occur.[111]

111 See Jane Perlez and Pir Zubair Shah, Drones Batter Al Qaeda and Its Allies Within Pakistan, N.Y. Times, April 4, 2010, http://www.nytimes.com/2010/04/05/wo...ef=instapundit.
This thread seems more appropriate for this article than the Drone Paradox thread (which deals more with the military and political aspects) - and it is O'Razor's thread.

Some general articles on "Just War Theory" (which has a large theological component):

Just War - Wiki

Just War Theory - IEP

JustWarTheory.com (many links to multi-variant sources)

War - Stanford Encyclopedia of Philosophy

Principles of the Just War

The concepts governing a "just war" can certainly vary - even within the same religious tradition. E.g., compare these Roman Catholic resources:

The Just War Theory: A traditional Catholic moral view

Catholic Just War

There Can Be A Just War: Teaching of St. Thomas Aquinas

There Can Be A Just War: Teaching of St. Augustine

Thus, no easy answers exist here; and one must credit Bill for tackling this subject (which I would duck).

Speaking of tackling, how many days to go until Navy beats Army ?

Regards

Mike