How do you prevent weapon of mass destruction damage?

Answer 1

Weapons of Mass Destruction fall into one of four categories: nuclear, biological, toxic, and chemical (though, some include toxic in either chemical or biological).

The nature of WMDs is that they are practically impossible to prevent damage from, short of stopping the weapon from detonating in the first place. Nuclear weapons are so powerful that even massively reinforced (hardened) concrete structures can be destroyed by them. Bio/toxic/chemical weapons are generally airborne, and incredibly hard to detect in many cases.

Realistically, BTC weapons can only be defended against by having full body protection suits worn by individuals, or specially designed buildings/vehicles with air filtration and other environmental controls. All of these are difficult, expensive, and impractical for large-scale deployment.

From a practical standpoint, protecting even modest number of people from any WMD attack is extremely difficult, and protecting property is impossible.