Well, to be honest, BTC was never meant to be used as war money, and I don't think it has been used as one, because that's simple money laundering, and BTC is not suitable for ML. You might not agree with me, but statistics show that BTC is the hardest way to land money.
Cash and fiat are more suitable for money laundering than BTC and people use it more for such purposes, but it doesn't mean BTC isn't used for money laundering, or to buy weapons or to do anything at all, take note that BTC is censorship resistant and permissionless and the owner can spend their keys however they like to do so, your keys; your coins.
It is worth mentioning that some people who use BTC do not understand it or know what their doing, some people even think that BTC is anonymous, they don't know that it is pseudonymous and if you want some level of anonymity you have to use CoinJoin services, people like these can use BTC for crime and even link their criminal activities to their real identities on centralized exchanges.