Like it or not, the Treaty on the Prohibition of Nuclear Weapons enters into force today. It is the first treaty that comprehensively prohibits nuclear weapons. Critics of the ban treaty say that the TPNW “would neither make nuclear weapons illegal nor lead to the elimination of even a single nuclear weapon”, and they are right because the nuclear weapons ban campaign had a different goal. It is a norm change campaign that makes a crucial step towards the abandonment of the old norm of nuclear deterrence and the practice it supports.

The 51^st anniversary of the Treaty of Tlatelolco is seeing yet another nuclear disarmament move in Latin America. Out of the five countries that have ratified the Treaty for the Prohibition of Nuclear Weapons (TPNW), three belong to Latin America and the Caribbean. While the region is taking the lead in promoting a nuclear-weapon-free world, it is necessary to reconcile nuclear and non-nuclear states in the 2020 NPT review cycle and find common ground on practical steps towards nuclear disarmament.

Am I trying to argue that the nuclear-weapon states should actually ramp up their nuclear arsenals? Absolutely not. To the contrary: I believe they already have more nuclear weapons than is genuinely necessary for national security purposes. The nuclear five should make responsible joint steps towards nuclear arms reductions. The United States and Russia should continue to lead the way by extending the New START treaty and developing joint measures - not necessarily in the treaty format – for deeper reductions in the second quarter of the 21^st century.