1. USA
Estimated Warheads: 7,650
Operational: 2,150
Reserve: 2,500
Retired, awaiting dismantlement: 3,000
First Test: 1945
Most Recent Test: 1992
It is estimated that about 500 warheads are assigned to land-based missiles, 1,150 are assigned to nuclear submarines and 300 are ready to be deployed on aircraft.
Also, as part of NATO's nuclear sharing program, an additional 200 B61 gravity bombs are deployed in five NATO countries: Belgium, Germany, Italy, the Netherlands and Turkey, the report notes.