According to an internal study of the U.S. Air Force most of the U.S. atomic weapons storage places in Europe are not conform with the minimal security standards of the Pentagon. Source: Federation of American Scientists [FAS]
The FAS estimates that 200 – 350 atomic weapons are stored in Europe. For example in Germany: Bundeswehr-Fliegerhorst Büchel / Eifel [map] On top of this there are other storage places Great Britain, Italy, Turkey and the Netherlands. The U.S. Military plans to reduces these places but not the atomc weapons.
The problems are: The security systems, fences, and that 9 month conscripts were used to ensure that the places are safe against thievery.
The study was only made public (due FAS), because the U.S. Air Force itself has big security problems: