If all the governments joined together in order to completely eradicate bitcoin from its core then there might be a tiny possibility that bitcoin might actually die. If all the governments take that step and make worldwide laws for bitcoin and stop all it's activities like trading, exchanging and mining then it would still take a long time to kill bitcoin as people would still secretly use it and as bitcoins transactions are anonymous it would be pretty difficult to completely stop it. But bitcoin surely will completely die if the community member starts backing up and lose faith in bitcoin and start isolating it, maybe then will the countdown begin.