I worked at the 3rd largest ISP in my country and I can tell you that if the government wishes to shut the internet down there are a few key points that they could physically destroy and you can't do anything about it. As soon as they destroy those key points you'd need actual physical cables going from your servers to another country to be able to reconnect to the world.
Unless you set up a complete MESH network. That would take a lot of towers, but it can be done on 2.4 GHz or digital HAM bands.