Possibility of Nation States influencing BTC or other Cryptocurrency markets?

My question is could an large nation state with significant economic power crash or boom the price of a cryptocurrency?

There have been many examples of traders like Soros crashing currency by publicizing large bets against the currency and pushing concerns about a countries' economy. If one were to publicize a large short on Bitcoin and attempted to cause a crash how would one succeed as this currency is not tied to single nation or economy and thus seems resistant to economic scares?

There are also nation states like North Korea recently releasing malware mining monero with cryptonight making millions. Proving a nation state can use cryptocurrencies to circumvent sanctions on their country. Could those actions inadvertently cause a crash in a crypto market due to large flood of miners and a dramatic increase of coin supply? Or can these nation states cause a boom by buying large amounts of coin due to increased demand?

If a nation state happens to buy a large reserve of a crypto currency could they drive the price down to zero by flooding the market with such reserve and in turn buy the worthless coin back effectively controlling the existing traded supply causing a large boom do to low supply of coin and seemingly higher demand?

These are a couple questions I am curious about and I'm interested what you all think about them?