Fish - I agree with you that a fair and timely trial is in everyone's interests, and is in fact a fundamental right in a democracy. The problem is what you do when that proves difficult or impossible to arrange.
We differ slightly though, in that I'm not sure that extending Geneva convention rights was all that reasonable actually. The people in Gitmo don't seem to me to have satisfied too many of the criteria which would grant them access to those protocols - specifically, they weren't organised in a clear chain of command, they weren't wearing uniforms and they don't subscribe to the laws of war. The Geneva Conventions say that if you don't play by the rules as soldiers, then the PoW rules don't apply to you. They were specifically written this way in an attempt to protect civilians.
The court also said that the military commissions violated Article 3 of the Geneva Conventions - which refer to "armed conflict not of an international nature" - ie civil wars. How madmen in Afghanistan plotting to blow up skyscrapers in NYC could be said to be in a conflict "not of an international nature" beats me. Guess that's why I'm not a Supreme Court judge..
And finally, to pick up on your point about the moral high ground - I'm not sure that we necessarily have to adopt that position. I'm reminded of a scene from the movie Mississippi Burning, about the pursuit of the Ku Klux Klan over the 1960's murders of civil rights workers. In response to a colleague questioning his interrogation methods, Gene Hackman says "these people crawled out of a sewer.....maybe the gutter is where we need to be [to fight them]"
A long bow perhaps, but if you take the view (as I do) that we are in a struggle to the death with these people, better be sure you don't turn up to the gunfight with one hand tied behind your back.....