I recently read an article on how best to survive in a nuclear explosion because the next world war will definitely be a nuclear war, Its advisable to build a cement building because its hard for radiation from a nuclear bomb fallout to penetrate them. I also advise you stock that place fully with food and water and entertainment for at least a year or two.
Under the current situation as a whole in the world, it becomes terrible and clear that we can not avoid war and at the same time with serious consequences. It's terrible to imagine what will happen, but if possible, it will be necessary to survive.