The funny thing is a state level actor can spend <0.01% of their defense budget to take control of >51% of the network.
That isn't even accounting for the fact they can knock others off the bitcoin network easily. If you have 10,000TH/s but cannot communicate with the network, that hash rate means nothing. DDoS or bad BGP routes, doesn't matter when the nodes have no way to talk.
The US has largest defense budget by far, and .01% would be less than $100 million, right? Could you really create enough mining capacity for that to take over the network?
Better question: by the time Bitcoin gets to the point that a government feels threatened enough to do this, will they be able to? And how will other governments respond? Will they start mining too so that no one government controls the network?
That isn't even accounting for the fact they can knock others off the bitcoin network easily. If you have 10,000TH/s but cannot communicate with the network, that hash rate means nothing. DDoS or bad BGP routes, doesn't matter when the nodes have no way to talk.