At twelve o’clock we flew over Hiroshima. We…witnessed a sight totally unlike anything we had ever seen before. The center of the city was a sort of white patch, flattened and smooth like the palm of a hand. Nothing remained. The slightest trace of houses seemed to have disappeared. 
Thus began the description of the Hiroshima tragedy provided by Dr Marcel Junod of the International Committee of the Red Cross (ICRC), the first foreign medical doctor to arrive in Hiroshima after the bombing.
His horrified report to the ICRC in 1945 began the tradition of physicians bearing witness to the catastrophic humanitarian impact of nuclear weapons. During the Cold War, physicians played a crucial role in warning the world of the devastating medical consequences that would result from nuclear war and alerting the public to the impossibility of mounting any meaningful response once these weapons were used.
In the United States, Physicians for Social Responsibility (PSR), in conjunction with medical schools across the country, organized a series of public symposia laying out in painful detail the destruction that would result from a single nuclear explosion and the devastation that a large-scale nuclear war would cause. The International Physicians for the Prevention of Nuclear War (IPPNW), the global federation of which PSR was the US affiliate, carried out similar work around the world; and for these efforts, IPPNW received the 1985 Nobel Peace Prize.
After the Cold War, the medical community, like much of society, acted as though the danger of nuclear war had ended also. Of course, the nuclear threat did not disappear. There are still nearly 15,000 nuclear weapons in the world, 95% in the arsenals of the United States and Russia. Recent events have made clear the very real danger that these weapons will be used.
After the Cold War, the medical community, like much of society, acted as though the danger of nuclear war had ended. Of course, the nuclear threat did not disappear.
The volatile situation in North Korea is the most visible nuclear flashpoint in the world today, but it is not alone. Relations between the United States and Russia have deteriorated dramatically since the Russian annexation of Crimea, and the new tension between the two has included explicit threats of nuclear war. Relations between the United States and China have also deteriorated. The situation in South Asia is equally worrisome, with fighting nearly every day on the border between India and Pakistan, nations armed with sizeable nuclear arsenals and military doctrines that call for the early use of these weapons in the event that daily skirmishes escalate to full-scale war.
Even a limited war between India and Pakistan, involving the use of just 100 small nuclear weapons detonated over urban targets, would kill 20 million people directly and would loft enough soot into the upper atmosphere to cause world-wide climate disruption. The resulting global famine could put some two billion people at risk.
A more extensive war between the United States and Russia would kill hundreds of millions of people outright and send enough soot into the upper atmosphere to create a nuclear winter, an instant ice age that would end most food production on earth and kill the vast majority of the human race. Along with the other nuclear armed states, the United States and Russia are engaged in an expensive effort to upgrade their nuclear arsenals.
In the face of this existential threat to human survival, IPPNW formed a broad umbrella coalition in 2007—the International Campaign to Abolish Nuclear Weapons (ICAN). During the ensuing decade, ICAN worked with a group of nonnuclear weapons states to promote a new treaty to ban nuclear weapons. On July 7, 2017, at the United Nations, 122 nations voted to adopt a new Treaty on the Prohibition of Nuclear Weapons (TPNW), which prohibits the development, testing, production, possession, use, or threat of use of nuclear weapons. For their work alerting the public to the resurgent nuclear threat and promoting adoption of this treaty, ICAN received this year’s Nobel Peace Prize.
At the time of the United Nations vote, the World Medical Association, the International Council of Nurses, the World Federation of Public Health Associations, and IPPNW issued a joint statement welcoming the TPNW as, “a significant forward step toward eliminating the most destructive weapons ever created, and the existential threat nuclear war poses to humanity and to the survival of all life on Earth.” But they also cautioned that, “the parties to the TPNW must now work diligently and urgently to bring the nuclear-armed and nuclear-dependent states into compliance.”
In the United States, a broad coalition of organizations has now launched a national campaign to promote a new nuclear policy based on an understanding of these medical consequences. “Back From the Brink: A Call to Prevent Nuclear War” calls on the United States to lead a global effort to prevent nuclear war by:
Renouncing the option of using nuclear weapons first;
Ending the sole, unchecked authority of any President to launch a nuclear attack;
Taking US nuclear weapons off hair-trigger alert;
Canceling the plan to replace its entire arsenal with enhanced weapons; and
Actively pursuing a verifiable agreement among nuclear-armed states to eliminate their nuclear arsenals.
It is critically important for the medical community to support this effort by educating the public about the medical consequences of nuclear war.
At this very dangerous moment, it is critically important for the medical community to support this effort by educating the public about the medical consequences of nuclear war. We need to speak out in our communities, adding a medical voice to the local campaigns that are forming to promote this fundamental change in US nuclear policy, and we need to mobilize our local, state, and national medical societies to echo the position adopted by the international medical community. In the venerable tradition of Dr Junod, we need to warn our patients of the great danger they face and urge them to support efforts to eliminate nuclear weapons as the only way to guarantee that they are never used.