Bitcoin and other crypto require a well functioning internet infrastructure, otherwise it's just data on a hard-drive.
Disconnect a country from the Internet (or filter the traffic) and you're forking the chain. Spend on both networks by buying other (unfiltered) crypto.
There are states (even large ISPs) that can do that.
Also, the first thing to go in case of global conflict is the global Internet. Countries will try to damage opponent's internet links to gain strategic advantage.
Crypto currencies will be useless in this case, losing all of their value.
There's always the concern of a bug in the protocol, a solution to the hash function or plain old human stupidity that can crash the currency.
I guess my point is: be careful, this is still very much experimental, don't invest everything you have in them.
Disconnect a country from the Internet (or filter the traffic) and you're forking the chain. Spend on both networks by buying other (unfiltered) crypto. There are states (even large ISPs) that can do that.
Also, the first thing to go in case of global conflict is the global Internet. Countries will try to damage opponent's internet links to gain strategic advantage.
Crypto currencies will be useless in this case, losing all of their value.
There's always the concern of a bug in the protocol, a solution to the hash function or plain old human stupidity that can crash the currency.
I guess my point is: be careful, this is still very much experimental, don't invest everything you have in them.