The nuclear ban treaty is set to enter force. Experts explain what comes next. – Bulletin of the Atomic Scientists

Seventy-five years after their destructive power was first unleashed, nuclear weapons are about to be officially and explicitly prohibited by international law. For the average person, it may come as a surprise to know that nuclear weapons, dreadful as they are, weren’t already outlawed. But for the vast majority of nuclear weapons experts, the ban will arrive far sooner than expected.

The Treaty on the Prohibition of Nuclear Weapons, informally called the ban treaty, was adopted with the approval of 122 countries at the United Nations in July 2017. It forbids anything and everything related to nuclear weapons, including their development and possession. It also obligates countries that join it to provide support to the victims of nuclear weapons testing and use, and to undertake environmental cleanup.

But to enter into legal force, the treaty needed more than just a vote at the United Nations; it needed ratification by at least 50 countries. It achieved that mark on October 24, after Jamaica, Nauru, and Honduras deposited the 48th, 49th, and 50th ratifications in rapid succession over the course of several days. Accordingly, the treaty will become official international law 90 days hence, on January 22, 2021.

The nuclear ban treaty is set to enter force. Experts explain what comes next. – Bulletin of the Atomic Scientists