Not only Bitcoin, the entire stock market was also in red after the news of war spread. This is understandable because bitcoin and stocks are both highly speculative assets, so people often decide to sell when there is negative news. This will always happen and is nothing new as they are ready to cut their losses and find safe havens to protect their assets in the long term. That is also the reason why gold always increases when war breaks out.
The market usually recovers afterwards because it adapts gradually, similar to what happened in the war between Russia and Ukraine which no longer has much impact on the market these days.
Source: CNBC