No, life sentence with a TV broadcasting real news 24/7 in his cell.
I want him to watch the world progress without him. To see his name slandered and shamed. To see his family exiled and his allies abandon him. I want him to know what it's like to be insignificant. To know that nobody will miss him and that he will never know pleasant company for the rest of his days.
Death is far too easy a getout for him. He deserves nothing less than to know his legacy died before it even began.
We can do all that, and then execute the traitor afterward. ---