They don't exactly have a lot of authority of foreign soil. It'd be like Greek agents going to Canada to try to manhandle a Greek citizen onto a plane without t

They don't exactly have a lot of authority of foreign soil. It'd be like Greek agents going to Canada to try to manhandle a Greek citizen onto a plane without the support of local law enforcement, and even that's very tricky. They just wouldn't have the authority to do so and would probably be in violation of local law. It would cause an even greater media circus. There's no such thing as pre-approving extradition. You couldn't, say, get the British government, a government that is quite amenable to extradition requests, to do so because he's not there. Extradition takes some time and is subject to local laws and its judicial system. It's not an easy or trivial process. Snowden's wise to make things public for his own safety and transparency. The US is showing no signs of letting up on attempting prosecute him under their laws. I'm not sure why you think it's unlikely he'd be prosecuted, especially as there seems to be more public apathy than backlash.