I think what happened when china banned Bitcoin is instructive to what would happen if a nation attempted to increase the energy prices for mining in it's borde

I think what happened when china banned Bitcoin is instructive to what would happen if a nation attempted to increase the energy prices for mining in it's borders - much of it moved to the next cheapest option, like coal plants in Mongolia, however being banned in China did decrease the price and use overall. Which is basically my point, you would be playing wack-a-mole with policy across the whole world trying to work on it from the supply side and energy prices, it will just keep moving to the most enviromental-legislation-lagging internet connected place. However, legislating the interfaces between your country and the network do drop the overall use and demand for mining effectively.