On the 75th anniversary of the bombings at Hiroshima and Nagasaki, we must redouble efforts to rid the world of nuclear weapons once and for all, write Vincent Ochilet of the ICRC and Niamh Lawless of the New Zealand Red Cross.

Today marks the 75th anniversary of the use of atomic weapons in conflict. As a Pacific nation we live in a region that knows too well what the use of atomic weapons means, and why these weapons must be banned for good.

It was 8.15 am on 6 August 1945 when a sudden blinding light engulfed the sky above Hiroshima. The bomb released a colossal force of destruction never before seen. A blast wave faster than the speed of sound expanded outwards, creating a massive firestorm, levelling the city and killing tens of thousands of civilians.

Three days later, on August 9, the city of Nagasaki suffered the same fate.

Neither city had nearly enough doctors, nurses or medicine to aid all the victims. Before the attack on Hiroshima, the city had 300 doctors. After the blast, only 30 had not been killed or injured. Of the 1,780 nurses there, 93% were dead or wounded.

Today, 75 years after the bombings of Hiroshima and Nagasaki, the dark shadow of nuclear war still hangs over all of us, despite the horrors those cities suffered. To this day, no city can prepare for an atomic bomb, and it’s hard for nations to effectively mount a humanitarian response to one. Thousands and even millions of civilians will be killed and injured, and no one will be able to help.

The Red Cross and Red Crescent Movement believes that it is a humanitarian imperative to ensure that nuclear weapons are never used again. What we cannot prepare for, we must prevent.

Many survivors of the Nagasaki blast “died within one to two months because there were no effective treatments, not even antibiotics or blood transfusions, and because the infrastructure was totally destroyed, including hospitals and pharmacies,” said Dr. Masao Tomonaga, a former director of the Japanese Red Cross Nagasaki Atomic Bomb Hospital, whose mother pulled him out of the rubble of their wooden home after the Nagasaki detonation.

In the months and years after those fateful early days of August 1945, tens of thousands of citizens of Hiroshima and Nagasaki suffered and died from cancers and other illnesses caused by exposure to radiation released by the atomic blasts.

The two nuclear bombs were uniquely horrific and terrifying weapons of devastation. The International Committee of the Red Cross (ICRC) and the Japanese Red Cross Society (JRCS) witnessed first-hand the suffering and devastation as they tried, in near-impossible conditions, to assist the dying and injured. The testimonies of survivors and first responders paint a chilling picture of unimaginable pain and senseless loss.

Marcel Junod of the ICRC was the first foreign doctor to reach Hiroshima one month later. “The centre of the city was sort of a white patch, flattened and smooth like the palm of a hand,” he wrote. “Nothing remained. The slightest trace of houses seemed to have disappeared.”

For 75 years, our knowledge about the catastrophic humanitarian consequences that nuclear weapons unleash has increased. Nuclear weapons have been detonated in peacetime too. Since 1945 more than 315 nuclear test explosions have been conducted in the Pacific, with widespread health and environmental damage caused. The impacts of these tests – for example, in damage to health or contaminated lands – spans generations.

New Zealand has opposed nuclear weapons since they were first used. It supported the first resolution of the first ever United Nations General Assembly in 1946, to ban nuclear weapons. Over the decades New Zealand has supported several international treaties to work for disarmament and the non- proliferation of nuclear weapons. Broad civil society and cross-party support in the 1970s and 1980s led to ground-breaking domestic legislation for a nuclear free New Zealand in 1987. New Zealand legal and diplomatic efforts have played a role in challenging nuclear tests in this region and in the development of international law; that the use of nuclear weapons would generally be contrary to international humanitarian law. More recently the country played a leading role in negotiating the 2017 Treaty of the Prohibition of Nuclear Weapons, and was the 14th country to ratify it.

Yet, internationally, far too little has been done to ensure that nuclear weapons are never used again. In fact, a disturbing record of close calls shows that we have been extremely lucky that nuclear weapons have not been used in armed conflict since 1945. We cannot expect that luck to hold forever.

There are more than 13,000 nuclear weapons in the world, many on ‘hair trigger’ alert status, ready to be launched at a moment’s notice. The risk that nuclear weapons may be used again is growing to alarming levels. New nuclear weapons are being developed. And treaties to reduce the numbers of nuclear weapons and the risks of their proliferation are being abandoned.

As a result, the world finds itself on a dangerous path towards a new nuclear arms race, threatening the very survival of humanity. This is a reality we cannot accept.

The International Red Cross and Red Crescent Movement was created to alleviate suffering, protect life and health, and uphold human dignity, especially during armed conflict and other emergencies. Use of nuclear weapons has the potential to render impossible the humanitarian mission our Movement exists to fulfil. We know today that any nuclear blast would cause insurmountable challenges for humanitarian assistance and that adequate assistance capacities do not exist at national or international levels. Who, then, will assist the victims of nuclear weapons, and how?

Our inability to answer this question means that the only responsible course of action is prevention.

Less than a month after the atomic bombings of Hiroshima and Nagasaki, the ICRC was already questioning the lawfulness of nuclear weapons, appealing to states to ban their use: “Only a unified world policy can save the world from destruction,” Dr. Junod wrote.

Three-quarters of a century later, we must be clear: We have waited long enough. Too often, the international community has been unable to prevent foreseeable crises. We still have a chance to prevent a global nuclear catastrophe. Our children and future generations should not have to bear the burden of our inaction.

Vincent Ochilet is Head of the ICRC Regional Delegation in the Pacific. Niamh Lawless is Secretary General of the New Zealand Red Cross.