The Treaty on the Prohibition of Nuclear Weapons (TPNW) is an ambitious international agreement aiming to completely eliminate all nuclear weapons in the world. Signed in July 2017 under a UN framework, it will come into force in January 2021, 90 days after the recent deposition of the 50th instrument of ratification. This has been celebrated by supporters as a great step toward total nuclear disarmament, to the point of declaring that “nuclear weapons are banned.” But a closer look at the countries which have – and most importantly which have not – ratified the TPNW reveals that, for the time being, the treaty’s real impact will be very limited, if not completely absent.