SCOTUS opinion available here:
CNN ex cerpts:
"The military commission at issue is not expressly authorized by any congressional act," said Justice John Paul Stevens, writing for the majority. The tribunals, he said, "must be understood to incorporate at least the barest of those trial protections that have been recognized by customary international law."
"In undertaking to try Hamdan and subject him to criminal punishment, the executive (Bush) is bound to comply with the rule of law that prevails in this jurisdiction," Stevens said. ...
Dissenting on the ruling were justices Antonin Scalia, Clarence Thomas and Samuel Alito. Scalia, in his dissenting opinion, used the word "mess" to describe the court's reasoning.
"The president's decision to try Hamdan before a military commission for his involvement with al Qaeda is entitled to a heavy measure of deference," said Thomas.
This case is way outside my area of expertise (I'm waiting for my biddy and international law expert Tony Arend to tell us what he thinks), but it does raise an issue about which I've been pondering lately: Is "war" the right metaphor for dealing with terror? Or should we accept that terror is really mainly a police/intelligence issue? If the latter is the right metaphor, this ruling makes more sense.