Regarding the Gitmo prisoners, I've said before that we should call them prisoners of war, give them Geneva Convention protections, and hold them until we sign a peace treaty with the Taliban and Al Qaeda (since Sara got on me last time for suggesting we hold them until they surrender). Do you think we should have started releasing the German POWs we held in 1943?Good idea.
Except that al-Qaida is a franchise, a meta-organization, and not a top-down hierarchy. Though I would suspect that bin Laden could issue a formal declaration of surrender, he doesn't have sufficient authority to order a diffuse organization with representatives in dozens of different countries to lay down their arms and be subject to criminal sanctions. The document you're asking for doesn't do what it might do when received from a nation-state.
On the other hand, Afghanistan is its own state, which has its own government and its own leaders. They have requested that Afghan nationals be repatriated, to be tried in Afghan courts. They've requested that 47 prisoners -- roughly half of the Afghan prisoners currently being incarcerated at Guantanamo Bay -- be immediately released. We don't have any reason not to do so. Not even the Afghan government, the government to which the prisoners would be the most threat to if th;ey were released inside Afghanistan, believes they'd be a risk.
The moderate position on this issue isn't "don't torture them, but hold them forever without trial," it's "repatriate, shut the facility, and hold accountable the people responsible for the idiotic policy that created it in the first place."