The consequence is simple: war makes people leave their homes, stop thinking about investments and worrying about food and basic things to survive, they don't think about investments. consequently there will be less money entering the market and also more people with fear will be selling their coins to use the money in the real world
Russia alone has no power to wage war against OTAN and the rest of the world together. China wouldn't go to war just to defend Russia, China wants to grow economically, they don't want war. That's why the cryptocurrency infrastructure will be safe because not all countries in the world would be affected, people would continue to mine bitcoin and altcoins and keep the network well and updating the code or introducing improvements. so don't worry about it