Two days at the end of the Second World War changed the world. Aug. 6 and 9, 1945, are the only two days in history when an atomic weapon was used in war. The Japanese cities of Hiroshima and Nagasaki were destroyed, and the world has lived with the possibility of mass destruction ever since.

The anniversary of these bombings should make us reflect on the choice to continue to maintain and modernize these weapons as a policy of the United States. We write as representatives of two groups in favor of changing this policy.

The organization Physicians for Social Responsibility wants the public to know that the destruction caused by a nuclear weapon would make an adequate medical response impossible for any country or international aid agency. Just considering the number of burn victims who would be among the casualties of a nuclear explosion illustrates this.

According to the American Burn Association, in all the United States, there are 128 burn centers with capacity to care for a total of 1,835 patients. A single nuclear weapon detonated over a U.S. city would result in tens of thousands of people needing burn center care that simply would not be available.

Nuclear weapons threaten all of humanity in our interconnected world. Physicians for Social Responsibility and International Physicians for Prevention of Nuclear War published a report in 2013, “Nuclear Famine: Two Billion People at Risk.”

That study models what would happen if the two smaller nuclear powers, India and Pakistan, had a war that involved using a combined total of 100 Hiroshima-sized nuclear bombs. This number is less than 1 percent of the world’s current number of nuclear weapons.

Because these two countries are so densely populated, in the following days and months, some 20 million people would die. The humanitarian consequences would not stop with that region of the world.

These nuclear explosions would cause massive fires across the two countries, putting so much soot in the air that the world would be blanketed. This resulting change in the atmosphere would block sunlight across the Northern Hemisphere. Analysis of the agricultural impact shows that over the following decade, 2 billion people could die of starvation.

For medical and humanitarian reasons, then, these weapons must never be used. The only certain way to ensure they are never used is to achieve the goal of nuclear disarmament.

Many religious leaders join these physicians in calling for nuclear disarmament. In July, the 10th Assembly of the World Council of Churches approved the Statement Toward a Nuclear-free World, asking its members for religious reasons to work for the goal of a nuclear-free world.

One paragraph of the statement reads, “To deploy nuclear weapons is to embrace what is arguably the greatest intentional risk in human history. … The fate of the earth has hung by the thread of this bizarre gamble for a lifetime. Surely, to persist in such a gamble makes a mockery of our Creator.”

There is a renewed commitment by countries of the world for humanitarian reasons to seek nuclear disarmament.

The countries of the world that don’t have nuclear weapons have held two international conferences on the humanitarian impact of nuclear weapons. In February, 146 states participated in the conference to consider nuclear disarmament and to assume, as stated by Austrian Foreign Minister Sebastian Kurz, “a global task and a collective responsibility.”

Nine nations of the world hold nuclear weapons, but the United States and Russia have almost all of them. Unfortunately, these nations have not participated in either of the international conferences. Maine U.S. Reps. Mike Michaud and Chellie Pingree and U.S. Sens. Susan Collins and Angus King should urge the U.S. State Department to attend the third conference in Austria in December.

The current news of the world gives daily evidence to the conflict over the many ideas and beliefs that divide the people of the world. The risk of these conflicts involving nuclear weapons, either by design or accident, threatens all of humanity.

In medicine, prevention of disease is better than a cure. Religions of the world ask us to turn from evil and embrace what God has given us for good. Our common humanity has made it possible to develop international bans on chemical and biological weapons. It is our responsibility to do the same for nuclear weapons.