In such an event, I believe the price of Bitcoin would plummet. What if it fell so low during the halving that miners couldn't recoup their costs? During a world war, I'm sure a lot of assets would be destroyed. But is BTC particularly vulnerable?
It's okay if the price of bitcoin drops so low and even if it did, I'm sure a lot of people would be very happy, especially those with a lot of money, because it's a golden opportunity that they won't get in the future.
And if a world war happens again, many or almost all assets will be destroyed, including bitcoin because bitcoin depends on the internet network.
But in the meantime, forget about the world wars and focus on the price and if the price drops again, the bitcoin price will be able to return to the high price. It can trigger a new ATH that will be higher than before.