They won't start war they adapt with bitcoin. I am sure because big banks are giving lessons about bitcoin to their employees i know that
Thats true. as an example we have Ripple, which is combining great with world banks. Also Russia is making its own crypto, to help its banking system.
The fact is that I noticed the movement even in totalitarian countries on the legalization of Bitcoin and work in the field of crypto-currency. I think that no banks will be at war with Bitcoin or other crypto currency. The fact is that the crypto currency is very good for today for all financial structures.