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Editor’s Note: Irwin Redlener, M.D., directs Columbia University’s National Center for Disaster Preparedness and is a professor of health policy and management at the Mailman School of Public Health. He was a former chair of the national executive committee of Physicians for Social Responsibility and is the author of “Americans at Risk: Why We Are Not Prepared for Megadisasters and What We Can Do Now.” The views expressed in this commentary are his own. View more opinion on CNN.

(CNN) —  

It now seems within the realm of possibility that over the next few years, the most important nuclear arms control treaties – negotiated among the world’s nuclear powers over nearly four decades of painstaking diplomacy – will have expired or been eliminated. This would open the floodgates to a 21st century arms race that could be far more chaotic and dangerous than what threatened the world following World War II.

Irwin Redlener
Irwin Redlener

Given this reality, we need to do everything in our power to re-establish agreements that will keep the world’s nuclear arsenal in check. With a presidential election on the immediate horizon, each candidate’s approach to the issue of nuclear weapons needs to be a centerpiece of discussion, not a mere debate question that is answered with the standard response that limiting access to nuclear weapons – particularly in key countries like Iran – is important. We must take seriously the severity of the threat we could face.

By 1961, the Cold War between the Soviet Union and the United States was already a superheated competition in which both nations sought to create larger arsenals of powerful nuclear weapons. Each side hoped that it would “win” by virtue of domination – a superior number of warheads and lethal delivery systems. While the balance overwhelmingly favored the US in the early 1960s, the global nuclear arsenal included well over 20,000 warheads, enough to destroy the planet multiple times over. By the late 1970s, the number of nations possessing nuclear weapons had grown to at least six, possessing nearly 50,000 nuclear weapons among them.

But what followed was a series of international agreements that sought to reduce the world’s nuclear arsenal and employ a number of safeguards intended to reduce the likelihood of an actual nuclear confrontation. Agreements such as the Treaty on the Non-Proliferation of Nuclear Weapons which became effective in March 1970 and a series of US-Soviet agreements beginning with the SALT Agreement in 1972, were each designed to create binding pacts to meet these goals.

Now, here we are in 2019. Long-standing arms control and non-proliferation agreements have cut the total number of nuclear weapons by over 75%.

But not only are the superpowers, America and Russia, still armed to the teeth, there are at least seven other nuclear-armed nations, like India and Pakistan, that remain ready to launch nukes under some level of actual or perceived provocation. There is Israel, a country that sustains a substantial nuclear arsenal as a deterrent to attack by hostile neighbors who continue to deny Israel’s right to exist. Then there are legitimate reasons to be concerned about rogue nations that are hell bent on acquiring nuclear arsenals of their own. North Korea, of course, is already there.

Last month, after years of US suspicions that Russia was not adhering to the Intermediate-Range Nuclear Forces (INF) Treaty, President Trump officially terminated it, signaling the beginning of the end of the arms control process that has regulated nuclear weapons since the Cold War.

And withdrawal from the INF Treaty raises concerns about the future of another crucial arms pact called New START, signed in 2010 by US and Russian Presidents Barack Obama and Dmitry Medvedev. Designed to limit the number of missiles and warheads possessed by the two nations, this treaty is set to expire in 2021, but can be extended under the now unlikely possibility that the two sides will agree to do so.

With the prospect of a world without arms control agreements and increasing international tensions, I worry about the intentional or inadvertent onset of a world-altering nuclear war, possibly well before the full effects of the climate crisis can even materialize. And we are increasingly vulnerable to cyberattacks that could trigger an unintended missile launch or cause a catastrophic miscalculation.

So here is the message that public health experts and organizations like Physicians for Social Responsibility want you to know:

If there were ever a nuclear war between the super powers, we would see massive fatalities and unimaginable numbers of blast, burn and radiation-related injuries that would not be manageable by any elements of the medical community that remained functional.

Moreover, the dust and debris rising into the far reaches of earth’s atmosphere would envelop the planet, creating what the late scientist, Carl Sagan, called a “nuclear winter.”

In essence, Sagan imagined the sun blocked out for years upon years, contaminating air quality and destroying agricultural capacity for the survivors of the initial attacks.

Where does all this leave us?

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Like so many other public health challenges – from lethal pandemics to the climate emergency – the only effective strategy of dealing with the catastrophic health impact of a nuclear war is prevention. And that means strong, verifiable agreements among nations to reduce the size of arsenals and impose every viable idea to ensure that nuclear weapons will never be deployed on planet Earth.

It’s encouraging that candidates for the presidency in 2020 seem to be seriously focusing on what’s to be done about the planet’s climate crisis. But they should be expected to convincingly answer this, too: What will you do to reduce the possibility of a major nuclear conflict, whether the onset is caused by a technical misread of an incoming attack, an accidental missile launch or an overt, deliberate world-changing act of aggression?