Iran has announced that it is now enriching uranium to 20%. Joe Biden is about to be sworn in as President of the United States. If those two things don’t terrify you, I don’t know what will. Natural uranium is useless in the construction of an atomic bomb. In order for the uranium to be useable the concentration of the Uranium-235 isotope, a tiny fraction of what is found in uranium ore, must be dramatically increased. The precise level of enrichment necessary is a state secret, but most open sources use figures somewhere between 80 and 90 percent.