Nuclear Free World Policy
These countries are weary of nuclear weapons’ deployment above everything else. Although 8 states are exempted from ban on nuclear weapons, 5 nations retain a de jure status of a “nuclear weapon state.” These states are the United States of America, the United Kingdom, the People’s Republic of China, France and Russia—all of whom had already tested nuclear weapons before the NPT was signed. NWS’s right to possess a nuclear arsenal is countered by Article VI of the treaty, which says that they have a legal obligation to eventually disarm. They also criticized NWS countries for failing to meet their obligation to disarm, in addition to criticizing the 3 states non-signatory nuclear weapons-capable states (which are considered de facto nuclear weapons states). This was stated in point 4 of the Joint Declaration of 1998:
History of nuclear weapons
Nuclear weapons possess enormous destructive power from nuclear fission or combined fission and fusion reactions. Building on scientific breakthroughs made during the 1930s, the United States, the United Kingdom and Canada collaborated during World War II, in what was called the Manhattan Project, to counter the suspected Nazi German atomic bomb project. In August 1945, two fission bombs were dropped on Japan, standing to date as the only use of nuclear weapons in combat. The Soviet Union started development shortly thereafter with their own atomic bomb project, and not long after that both countries developed even more powerful fusion weapons known as "hydrogen bombs".