sentences:  Indeed, the strategic attacks on Hiroshima and Nagasaki utilized weapons of between 10 and 20 kilotons, but that was because the "Little Boy" and "Fat Man" bombs were the most destructive and indeed only nuclear weapons then available.There is no precise definition of the "strategic" category for either range nor yield.The yield of tactical nuclear weapons is generally lower than that of strategic nuclear weapons, but larger ones are still very powerful, and some variable-yield warheads serve in both roles,l.