Some interesting concepts and questions raised in this article. What it doesn't answer is how many "unfortunate, but unintended collateral damages" have to be in the "kill box" before it becomes morally and legally unsupportable?
Ask yourself this question "If Osama bin Laden had been hiding inside a refugee camp containing 10,000 people (none of whom knew his real identity) and the only way that you could be sure to "neutralize" him was to carpet bomb the refugee camp and kill everyone in it using chemical weapons - would it be right to do so?". Then answer the questions below:
[A] If the answer is "Yes.", please explain how you are going to justify yourself to the relations of the 10,000 "unfortunate, but unintended collateral damages".
[B] If the answer is "No.", please provide the number to substitute for "10,000" and then answer question [A] with that number substituted for the number "10,000".