If the United States goes to war with Russia, more allies like China and Iran will definitely come to Russia's aid, and that means starting a world war! Bitcoin has never been in a world war and we do not know how it will react to this situation!
That is what I'm curious about it but if we will base on the second World War, the stocks at that time made a huge drop and there is a chance that it might happen again this time if a world war happens again (hope not) and since the price movement of stocks and crypto are correlated with each other then we might assume that crypto alongside stocks will go down as well.
Now with regards to a possible WWIII, I don't think that it will happen and I don't think that other countries will try and help Ukraine since they aren't a member of NATO.