Nuclear blind man's buff

摘要

How do you know that an item concealed in a box is what you are told it is if you are not allowed to measure the properties of the item through the box walls? This is the problem faced by inspectors in satisfying themselves that the item is a nuclear warhead. Instruments based on γ-ray and neutron spectroscopy could tell us that the box contains a certain amount ('x' kilograms) of plutonium-239. But because such measurements would reveal warhead-design information that could assist weapon proliferation, their full use contravenes the Treaty on the Non-Proliferation of Nuclear Weapons.