In 1945 nuclear weapons were used in armed conflict for the first and only time. 355,000 people were killed in Hiroshima and Nagasaki by two nuclear bombs. Two. That number alone puts in stark perspective the world’s current arsenal of about 13,000 nuclear weapons. And yet in many ways the 13,000 weapons held globally represents progress; it’s less than a quarter of the more than 63,000 weapons in circulation in 1985 during the cold war. But what John F Kennedy said in 1961 at the United Nations is as urgent now as it ever was: “We must abolish these weapons before they abolish us.” Over the more than 50 years since the inception of the nuclear non-proliferation treaty it’s played an important role in lowering the risk of these weapons abolishing us. In addition to the near 80% reduction in nuclear weapons, the treaty has also contributed to keeping a lid on the number of countries acquiring them. More countries have ratified the treaty than any other arms limitation and disarmament agreement. Right now in New York, there is an opportunity to go even further. And we must. Our world is at greater risk of nuclear catastrophe than at any time since the height of the cold war. Growing superpower tensions and two decades of stalled progress on arms control have pushed the risk of these weapons closer to reality. Currently 191 countries are meeting at the UN to renew the nuclear non-proliferation treaty and negotiations are going down to the wire. These talks offer a chance to breathe new life into nuclear disarmament at a time when the world needs that more than ever. Nuclear catastrophe is not an abstract threat but a real world risk. Nuclear weapons could be deployed in a conflict, as Russia’s president, Vladimir Putin, has intimated, or they could be deployed by miscalculation or mistake – real possibilities in times of heightened tension. New Zealand is calling on the nuclear weapons states – the US, Russia, China, France and the UK – to step back from the nuclear abyss, and provide that leadership by committing to negotiate a new multilateral nuclear disarmament framework. But from one of the best geographical positions in the world to be should nuclear fallout occur, why does New Zealand feel so strongly about this issue? We are a Pacific nation. Our region bears the scars of decades of nuclear testing, on both the people and the lands and waters of our region. That’s why for 35 years New Zealand has been proudly nuclear-free and an international advocate for a world free of nuclear weapons. This does not mean we are naive to real world dynamics, nor does our geographic location mean we have the luxury of a moral stance that others do not. In fact, New Zealand’s message – that nuclear weapons do not make anyone safer and no longer have a place in our world – reflects the view of the overwhelming majority of countries. We just need to believe a different approach is possible. We only have to look back in our history to map a path to a safer future. The lessons of Hiroshima and Nagasaki, and of testing in the Pacific, are reminder enough that there is never justification for the deployment of nuclear weapons. The challenges of agreeing multilateral nuclear disarmament can seem overwhelming. But it’s not a task that can be put off indefinitely. Right now, the treaty is under stress. It is affected by geopolitical developments including tension between the nuclear weapon states. But, more fundamentally, there is growing scepticism and frustration about the intention of the nuclear weapon states to ever fully implement their nuclear disarmament commitments under the treaty, with those states arguing the global security environment makes doing so too difficult. If this continues, there is a real prospect of countries losing faith in the treaty – putting at risk both the treaty’s role in progressing nuclear disarmament, and in preventing the spread of nuclear weapons material. There is a lot at stake in New York this week. Some might say that in the current global environment a new nuclear arms race is inevitable, and with it a further undermining of our nuclear disarmament and non-proliferation efforts. But I cannot accept a logic that suggests insecurity and instability render us incapable of doing the very thing that would help make the world less insecure and less unstable – an idea that the history of the treaty itself shows is false. There can and should be a different trajectory – one of urgent leadership, of recognition of the nuclear precipice on which we are all standing, and of continued progress in our efforts to rid the world of nuclear weapons. It’s not only possible – it’s necessary. Jacinda Ardern is the prime minister of New Zealand