On Tuesday, 29 Dec 2011 the Senate voted against changing provisions in Senate Bill 1867 (S. 1867), the National Defense Authorization Act (NDAA) that would require the military to indefinitely detain anyone, anywhere at home or abroad that is a threat to the United States. As McCain inferred on the Senate floor 'whether they're a citizen or not'.
These provisions would at best confuse our efforts in anti-terrorism and set an ugly precedent to decide what a 'threat' is to America. Criminals are a threat to America. Drug users are a threat to America. Democrats are a threat to America (recalling political mudslinging from 2004 and 2008). Finally, as Rand Paul mentioned somewhere: a state of perpetual war precludes the possibility of victory. Don't give the DOD an impossible mission.