It merely requires massive amounts of electricity and e-waste vastly disproportional to its benefit and proportional to its price. Don't mince words.

Proof of stake is just a fork that'll happen whenever there's enough force applied by the power providers.

This excess low cost energy that can't be moved easily to other areas is often the only kind of energy bitcoin can use to win the economics of btc mining. It in fact subsidizes a lot of green energy and makes it more viable in the longer term.

Not following this line of thinking now. How does the military enforce scarcity? Also, scarcity of fiat currency is relative to the amount of goods and services available for sale in the economy and the demand for them.

What stops other nations from simply printing your currency?

https://www.google.com/search?q=north+korea+counterfeit