In July 2017, 122 countries voted in favour of the Treaty on the Prohibition of Nuclear Weapons. Nuclear weapons were the only weapons of mass destruction without a treaty banning them, despite the fact that they are potentially the most potent of all weapons. Biological weapons were banned in 1975 and chemical weapons in 1992. This new treaty sets the international norm that nuclear weapons are no longer morally acceptable. This is the first step along the road to their eventual elimination. The signing was preceded earlier in 2017 by an open letter calling for nuclear weapons to be banned signed by thousands of scientists, including 30 Nobel Prize winners.
The U.N. Convention on Certain Conventional Weapons has 129 full members who foreswear the use of what the U.N. considers "inhumane" landmines.