I used to think this as well and even offered suggestions on HN for countries that were being blocked. In hindsight I feel that may have been a sub-optimal decision on my part. They need to first communicate with one another in their nation and find a way to rise up above the tyranny. The outside world will do little help with this. Physical blockades will make them desperate and force hard decisions and sacrifice. Every nation has to go through these awful growing pains. But ripping off that bandage is a big topic for another thread I think.
This is misguided, naive, and even arrogant. Instead of playing the group identity game and anthropomorphizing lawnmowers, imagining what someone must do, you need to understand how totalitarian systems work, there's no "government" and "people" as separate entities to clash, and no "dictators" either. There is simply no "they" to communicate to one another, and there's no communication/organization possible, as the system removes any means for doing that. Paradoxically, any totalitarian system is decentralized and stuck in the local optimum.
Totalitarian systems are perfectly in balance while being isolated, and in fact always move towards self-isolation - take imperial Japan, USSR, or any other similar society. When your goals are the same as those systems', you should take a long look at what you're doing. It's often said that "Jeans brought USSR down", meaning the cultural influence of outside world. Discarding that is just stupid, it's the most fundamental leverage you have at your disposal.
I will also let you know that many neutral countries receive our internet through some of those you imply by your statement. You would cut significant chunks of mostly poor population off the internet. We have some connectivity through other countries, but it will be back to the dial-up days for at least 5-10 years until more fiber is laid out.