I would bet you're wrong, and they would owe it all to Jihad Johnny.
JJ is going to get a standard-issue trial in the U.S. for non-capital crimes. I don't think they can execute the Moussawi dude they caught in Detroit either, even though he may face capital charges. First, he didn't actually do the deed, second, he's got a French mommie w/a squadron of lawyers.
Under these circumstances, I don't think the U.S. can get away with execution of foreign nationals held in Cuba. Nobody's going to buy a story that makes some subset of them more guilty than JJ and the rest. Death sentences would be a shot in the arm to the Euro-left. The Bushies might be able to understand that.
More generally there is the fuzzy classification problem. If the prisoners are POW's, they are perhaps subject to military tribunals, but also to the strictures of the Geneva Convention. If they are criminals, on the other hand, they are entitled to trial by jury and all that, especially if that is what JJ gets. Didn't Noriega get a full trial?
By inflating OBL so much, the U.S. looks thuggish when it drops a ton of bricks on the head of poor JJ. A great cause needs a great foe, and a great exercise of justice needs a great criminal. But the great foe is out-of-pocket at the moment, perhaps forever, and instead of a great criminal they have a wayward hippie and some guy who wasn't competent enough to contract for flying lessons.
I would call this the ideological dimension of imperial overstretch. Much harder than blowing people up. Bush's political problem in Europe is the opposite of his present political ascendance in the U.S.
mbs