With US bombing Iran, talks of WW3 seems closer and closer. I am, of course, not wishing for this to happen as nothing good will come out of it. But let us think for a second how will bitcoin be useful to us should WW3 actually happen? First of all, expect chaos. Fiat Currencies would most likely decline. Governments would need to print more money to budget for fighting other countries. This will surely lead to inflation. This is where crypto would come in handy. Bitcoin can be a safe haven for most.
The most important thing is if you live in a country directly affected by the war, surely people would migrate and seek shelter. Bitcoins can be helpful for doing this as you will not be carrying your country's local currency. I am sure now that people would be buying crypto in fear of the war happening.
Bitcoin's decentralized structure can provide some advantages in global crises such as war, but it should not be forgotten that it also has limitations. Bitcoin is not dependent on any central authority, bank, government.
In a scenario where financial systems collapse due to war or banks become inoperable in some countries, it may be possible for the Bitcoin network to continue to operate as long as there is an internet connection, if there is no internet connection, there is no access. If a country's currency collapses due to war, Bitcoin can be used as an alternative to the local currency, quickly and practically.