> Why do you think the government would have to produce new ASICs, when they could just buy or seize the existing ones?

There is not enough of them to buy on the market to make 51% attack. Of course seizing is possible but hard because I imagine it would be quite hard to locate them, apart form large mining operations they are quite distributed.

In case of bitcoin network it would have to be a large multicountry operation. Because the miners are really distributed around the world.

They could just subpoena websites and retailers that sold them previously and start there.

That would take out the "most developed countries" part...