With the 50th ratification of the Treaty on the Prohibition of Nuclear Weapons (TPNW) today, nuclear weapons will now be categorically outlawed under this treaty, when it enters into force 90 days from now. This is a key moment of change in the history of nuclear weapons.

Ever since their invention, there has been sustained opposition to nuclear weapons because of the horrific and catastrophic impacts for people and our environment they have produced Рand would produce if they were ever used again.

In recent years, a renewed movement amongst states, international organisations and civil society to examine and take these humanitarian impacts seriously has led to a growing rejection of the legitimacy of nuclear weapons amongst these broad constituencies, and a strengthening of the norm against their possession.

This resulted in the key moment of the agreement of the TPNW in 2017, negotiated by over one hundred states on the basis that a legal prohibition was the only morally tenable and legally coherent response to the humanitarian impacts of nuclear weapons.

The outlawing of nuclear weapons by this international treaty, which will come into effect with the 50th ratification today, is the latest milestone in the development of this trajectory of the growing, global rejection and stigmatisation of nuclear weapons. This will help to create the conditions for their elimination, through further challenging and marginalising the acceptance of the possession of weapons of mass destruction as “responsible” for any state, and the role of such weapons in international relations.

This is not a process that will happen overnight. The entry into force of the TPNW is a step in this norm building process. It shows the will of countries to draw a legal line against nuclear weapons – in the face of considerable opposition from the nuclear-armed states to the negotiation and then ratification of this treaty. As well as a demonstration of this will, entry into force has practical impacts, for example by prohibiting assistance to nuclear weapons activities to states party to it. This could have consequences for investments in nuclear weapons producers – both via new national laws, and generally through the growing norm against nuclear weapons.

Nuclear weapons are a concern for, and affect, all countries and people – not just those who endorse these weapons as part of their international strategies. Now that it is set to enter into force, the Treaty on the Prohibition of Nuclear Weapons will provide an international framework under which countries, international organisations and civil society can continue to work together over the coming years to build the norm against nuclear weapons. The treaty centres the importance of the people and places affected by nuclear weapons – rather than those that possess them – including through its humanitarian foundations, and its specific provisions requiring that parties assist communities and work to remediate environments already impacted by nuclear weapons testing and use.

The 50th ratification of the TPNW today marks a key point on the road to the end of nuclear weapons.

Featured image: © ICAN, Aude Catimel