No one as of today is rich enough to create create enough ASICs to control 51% of the network. Moreover in fact you need a bit more than that.
A Government could do it quite easily. Or as someone pointed out earlier in the thread, the Chinese government could march in to mines in its country and take over more than 75% of the hashrate anyway, which is a risk with bitcoin.
My view is that most Governments are simply not interested enough to do this.
I dont think its easy as you say. If you think abot the enery to be wate in this hashrate and the atual "enery crise"(coal...) the govern will not incentive/force this expensive activity only to destroy a cryptocurrency.
I said they
could do it quite easily. I qualified that at the end of my post with the point that you make that they are not interested enough. Lets look at facts. The European bank is printing 60 billion euros a month - and its currency is strengthening, that means they are printing more than the entire value of bitcoin every 3 weeks or so. So why would they want to do this? But IF they did, then they would more than have the resources to do so.
But as per my knowledge, in recently have some rumor about Russia government has spend $100 million for support community miner Bitcoin in their country for compete miner in China. This is positive signal about government in some country still interested Bitcoin and cryptocurrency.
Instead on making this kind of attack or plans on destroying on Bitcoin,
russia have been decided to go in mining field which is really a nice thing and about on the 51% attack on bitcoin wont really be sufficient enough considering on the hashrate its too big and even government do have the power i dont think they will jump in to this aims or goals on controlling or blocking bitcoin. Its not possible its soo damn vast.
These are just rumors
Well, those might not be quite rumors but rather speculations by some people allegedly close to Putin but regardless, it makes no sense for Russia to mine Bitcoin and compete with China (which would be a losing battle anyway). If anything, Russia would rather try to push their own crypto, but personally, I believe in neither possibility. In other words, these are most likely just empty talks