Is this because he was arrested in the ZI (Zone of the Interior) instead of Afghanistan or Iraq? Presumably you would not have required a status hearing for the 210,000 US citizens detained during the American Civil War (because they were Confederate Soldiers). I assume that some of those POWs were arrested off the battlefield by civilians when attempting to escape and evade after a defeat.
The court seemed to establish a bright line between a foreign battlefield and ORD (where Padilla was arrested). Is that bright line sustainable when 70%+ of the combat casualties suffered in this war were suffered in Zip Code 10048 one mile from where I'm sitting right now? Isn't NYC a battlefield in this war? And isn't the civilian air transportation system (including ORD) a battlefield?