Most of the world's banks, whether big or small, are located in the US and Europe, In case of war, all banks will be closed, Which will immediately benefit Bitcoin, The price of bitcoin will increase infinitely, Many banks will quickly print dollars and euros to buy cryptocurrency quickly, This will have a huge impact on Bitcoin as there will be no other source for cross-border transactions. Remember that most of the world's banks are located in the US and Europe, while 20-25% of them operate in Asia and other regions.
I don't know what makes you imagine that America and Europe will go to war because they are quite close so it would be very strange if America and Europe went to war, maybe it would be more logical if America and Russia went to war, or America and China. But no one wants a war between us because if that happens then the results will be worse than any war that has ever happened before and I can't imagine that happening.
Moreover, when there is a war, whatever the price of Bitcoin at that time, not many people care, security and life are more important than anything. Printing money to buy bitcoin?? It's not that easy guys, the financial system will collapse if this is done and inflation will get worse because of the impact of war and money printing. I think the financial system is very complicated and if there was a big war it would be even more difficult