I realize no politician of any stripe will say it, but the risk to the populace for moving all Gitmo detainees to the United States is vanishingly small, and with a very small amount of ingenuity, damn near zero. Let me show you, using logic and grade-school math skills, why that is so.
There are currently about 240 detainees at Guantanamo. We know little about most of them, of course; but an analysis highlighted by Jeralyn in 2006 showed
Only 5% of the detainees were captured by United States forces. 86% of the detainees were arrested by either Pakistan or the Northern Alliance and turned over to United States custody. This 86% of the detainees captured by Pakistan or the Northern Alliance were handed over to the United States at a time in which the United States offered large bounties for capture of suspected enemies.
If that's accurate, few detainees can even speak English. It also means few detainees have been in the United States. Now picture one of those detainees busting out of solitary confinement from a United States prison. Where, exactly, do they go? How do they manage in an unfamiliar country without the local language, with no money?
Did somebody say that our escaped terrorist would get in touch with al-Qaeda for assistance? Jeralyn again:
Only 8% of the detainees were characterized as al Qaeda fighters. Of the remaining detainees, 40% have no definitive connection with al Qaeda at all and 18% are have no definitive affiliation with either al Qaeda or the Taliban.
Let's suppose, though, that our escapee is an al-Qaeda fighter. It's been as many as seven years since he has had contact with the group. Any terrorist organization is by definition dynamic -- it has to be, to evade the other side. The chances our al-Qaeda escapee can find the channels to communicate again with al-Qaeda are very small. Then again, al-Qaeda isn't likely to want contact with a fighter who has been in close contact with us. Who knows which side our escapee is on now?
As for our escapee causing mayhem -- I've already sketched out the difficulties he will have just surviving. One hallmark of al-Qaeda's terrorism has been close coordination, either from central command or teamwork in a cell. Our lone escapee has no one with whom to coordinate.
Finally (even though we're down to nearly impossible), let's consider the possibility of several escapees creating a cell to commit acts of terrorism. Pretty hard for several of you to escape together, since you're all in solitary, just as you were for years in Gitmo. It would be even harder if you're in solitary in separate prisons across the country. It becomes pretty much impossible if those in solitary in any given prison have never even met each other. Since these detainees were picked up all over Afghanistan and Pakistan, mostly by bounty hunters, there's a good likelihood that the population could be divvied up in such a way that coordinated escapes are impossible.
The bottom line: Unless an escapee has magic powers, his ability to survive day to day, let alone reach al-Qaeda, recruit or reconstitute a cell, and then plan and execute an attack on US soil is just about nil.