It is not an "atomic" bomb. The dirty bomb is a conventional weapon using conventional explosives (such as dynamite or TNT) to disperse or spread radioactive material. The dangerous part of the weapon is the explosive itself, not the radioactivity that would be spread.

In 1950, US president Harry S. Truman publicly stated that the use of nuclear weapons was under "active consideration" against Chinese targets during the Korean War. In 1953, US president Dwight D. Eisenhower threatened the use of nuclear weapons to end the Korean War if the Chinese refused to negotiate.

A dirty bomb, or radiological dispersion device, is a bomb that combines conventional explosives, such as dynamite, with radioactive materials in the solid, liquid or gaseous form. A dirty bomb is intended to disperse radioactive material into a small, localized area around an explosion.

Nonetheless, despite thefts and trafficking of small amounts of fissile material, there is no credible evidence that any terrorist group has ever obtained or produced nuclear materials of sufficient quantity or purity to produce a viable nuclear weapon.