Senator Lieberman says he plans to introduce a bill which would expand the provisions which already exist in law for removing U.S. Citizenship from those who serve in the military of another country, in order to also strip citizenship from anyone who acts in cooperation with a designated terrorist organization. I could, perhaps, see certain situations where this might be appropriate. If a US citizen was captured in a combat zone, fighting for some non-state-entity which had been designated a terrorist organization, I could see designating that person an enemy combatant — for the same reason that it makes sense to do so with non-citizens who are fighting U.S. forces in combat zones without belonging to the military of a specific country. Our rules for dealing with P.O.W.s don’t really work when applied to people fighting for non-state entities, since there’s no organization to eventually accept peace and end the way with terms and exchange of prisoners.