With so much uncertainty as to the location of all nuclear weapons ever made how can nuclear blackmail be prevented?

Question on @Quora: With so much uncertainty as to the location of all nuclear weapons ever made how can nuclear bl…

A Nuclear Needle in a Haystack: The Cold War's Missing Atom Bombs – SPIEGEL ONLINE. There are numerous articles and reports that report that the World does not know where all the nuclear weapons ever made are. This also includes the material to make nuclear weapons.

With so much uncertainty as to the location of all nuclear weapons ever made how can nuclear blackmail be prevented?