Do you expect bitcoin and other cryptocurrencies to go down in price ? As people will swtich to hard cash or gold?
Note : There are wide power outages, servers getting down, no electrictiy and everything bad you can expect if WW3 happens
It is no longer possible to have a world-wide war. No country will want to have such a catastrophe.
The 1st and 2nd world wars produced very negative consequences for humanity. I do not think they will want to live this again.
But suppose you have something like that. If is not exist in the digital world and electricity the bitcoin value will be $ 0.