From page 6 of the whitepaper:
"In the circumstances here, the interests on both sides would be weighty... An individual's interest in avoiding erroneous deprivation of his life is "uniquely compelling."...No private interest is more substantial. As the Hamdi plurality observed, in the "circumstances of war," ''the risk of erroneous deprivation of a citizen's liberty in the absence of sufficient process .. . is very real," id. at 530 (plurality opinion), and, of course, the risk of an erroneous deprivation of a citizen's life is even more significant.
"But, ''the realities of combat" render certain uses of force necessary and appropriate," including force against U.S. citizens who have joined enemy forces...
"In view of these interests and practical considerations, the United States would be able to use lethal force against a U.S. citizen, who is located outside the United States and is an operational leader continually planning attacks against U.S. persons and interests, in
circumstances: (1) where an informed, high-level official of the US Gov't has determined the target individual poses an imminent threat of violent attack against the United States; (2) where a capture operation would be infeasible-and where those conducting the operation continue to monitor whether capture becomes feasible; and (3) where such an operation would be conducted consistent with applicable law of war principles."
Also, try to remember the SOURCE of the commentary. Reason.com is one of those very partisan places (though not as bad as the Free Republic) that produces and distributes highly questionable material with the intent of "stirring up the base".