Even during a possible WW3 bitcoin will still exist by the bias of military networks that could use bitcoin to send payments to troops or guns...
You think that in WW3 we will use a lot of soldiers and currencies will be valid?
You're very much mistaken.
That depends on a lot of factors, starting by "when its going to be the next WW", not wishing it tho.
Currencies are always valid, we can change the type of the currency but we do need to keep paying war costs.
but one thing we can be sure, crypto currencies are here and going to stay alive, then can evolve, mutate but the concept it's always there.
What better then crypto currencies to pay for war costs anonymously .
but that's just my opinion...