Clearly the US government have to prosecute him with something. Cant encourage it and all that. And presumably he leaked this info knowing full well that the US government would have little choice but do this.

So, I suppose the perfect out come would be: go back to the US, get charged, go to court, admit guilt, get sentenced, then hopefully a President can pardon him.

Now, how one can ensure such an out come, I have zero idea.

All assuming he gets to go to proper civilian court with a jury. If its a military, kangaroo, secret, closed, court.... no way.

Yeah, I like the idea, I just cant see it working or having a viable chance.

Pity.