A man watches a TV news program reporting about a missile launch in North Korea. (Lee Jin-Man/AP)

Dan Zak is a reporter for The Washington Post and author of “Almighty: Courage, Resistance and Existential Peril in the Nuclear Age,” a book about nuclear weapons and anti-nuclear activism.

Hillary Clinton and Donald Trump agreed on one thing at this past Monday’s presidential debate: Nuclear weapons are the single greatest threat to U.S. security. The candidates’ concerns diverged from there. Clinton praised the controversial nuclear deal with Iran and worried about nuclear terrorism. Trump said that the U.S. nuclear arsenal is not keeping pace with Russia’s. Nukes have been shrouded in myth since they were credited — improperly, many say — for ending World War II by destroying two Japanese cities. Seventy-one years later, and decades after the end of the Cold War, these weapons continue to bedevil diplomacy, discourse and the planet itself.

Myth No. 1
Nuclear weapons haven’t been used since Nagasaki.

In 2008 Cambridge University Press published a book titled “The Nuclear Taboo: The United States and the Non-Use of Nuclear Weapons since 1945” by international relations scholar Nina Tannenwald. The suggestion — that nuclear weapons haven’t been used whatsoever since the bombing of Nagasaki — has made its way into textbooks and magazines, with one 2014 Boston Review article wondering “nuclear weapons haven’t been used since 1945. Is the persistence of the arsenal really a problem?”

Although nuclear weapons have not been used again in combat, they’ve been detonated 2,055 times since Aug. 9, 1945, mostly by the United States and the Soviet Union. These tests have been both demonstrations of force, and experiments with weapon design and effectiveness. From 1946 to 1958, for example, the United States exploded the equivalent of 1.6 Hiroshima bombs every day in the Marshall Islands to study the weaponry and intimidate Moscow; the USSR wrought similar devastation near the Arctic Circle and in present-day Kazakhstan.

In September, North Korea — the only nation to test nuclear devices in the 21st century — conducted its fifth underground detonation to assert its position in geopolitics and to coerce its enemies. And although the United States doesn’t conduct full-scale testing, Pentagon officials like to say that American nukes are used every second of every day, as a deterrent.

“Across the Atlantic, we’re refreshing NATO’s nuclear playbook” to “deter Russia from thinking it can benefit from nuclear use in a conflict,” Defense Secretary Ashton Carter said Thursday.

Myth No. 2
Nuclear weapons keep the peace.

“The sensible path to peace starts with the realization that peace can be secured only through strength,” Robert Spalding, a military fellow at the Council on Foreign Relations, wrote in The Washington Post in 2013, adding that “nuclear weapons represent that strength.” In 2009, Jonathan Tepperman, then deputy editor of Newsweek International, argued that nuclear weapons ensure peace by “making the costs of war obvious, inevitable, and unacceptable.”

Yet Richard Nixon’s madman theory — that he should be viewed as crazy enough to unleash nuclear weapons in the Vietnam War — neither curbed bloodshed nor cowed Moscow and the Viet Cong. The Cuban Missile Crisis did not result in nuclear war, but John F. Kennedy made decisions that might’ve led to one:

“If fear of nuclear war prevents leaders from taking steps that might lead to nuclear war, and if Kennedy knew that blockading Cuba might result in nuclear war, then why wasn’t Kennedy deterred?” Ward Wilson wrote in his book “5 Myths about Nuclear Weapons.”

Indeed, nuclear weapons have helped instigate conflict without even existing. The mere rumor of a nuclear program in Iraq and the thought of Saddam Hussein supplying his nukes to terrorists was enough to send the United States into a costly war, now in its 14th year, that has upended the Middle East.

Myth No. 3
Nuclear terrorism is likely to happen.

President Obama calls nuclear terrorism the most serious threat to global security and peace. Former defense secretary William Perry says we are closer to nuclear catastrophe today than at any point during the Cold War, in large part because of terrorist ambitions. At a 2015 security conference the State Department’s top arms-control official, Rose Gottemoeller, proposed that“nuclear terrorism is the most immediate and extreme danger facing our nation.”

In reality, though, that’s a “high-consequence, low-probability event,” retired Los Alamos chemist Cheryl Rofer told the Arms Control Association earlier this year. “There have been a number of articles that talk about a market in nuclear materials. Now in order to have a market, you need a seller and a buyer. And as far as I am aware, there are not any buyers out there. . . . In any case, if a terrorist group could get, say, sufficient enriched uranium to make a bomb, would they be able to make it? There are lots of things that can go wrong.”

A non-nuclear explosion laced with radioactive materials (a dirty bomb) is a more likely and far less destructive scenario: Since 1995 there have been 2,889 confirmed cases of lost, stolen or misused nuclear or radioactive material, according to the International Atomic Energy Agency.

Also more likely: a major nuclear accident. From 1950 to 1968, at least 1,200 nuclear weapons were involved in “significant” incidents in the United States, according to Eric Schlosser’s book “Command and Control,” which details a 1980 explosion at an Arkansas missile silo that threw a thermonuclear warhead into the sky. And from 2009 to 2013 there were 1,500 reportable incidents involving U.S. nukes or the systems that manage them, according to the anti-nuclear nonprofit Global Zero.

Regardless of the odds, Harvard’s Project on Managing the Atom still sounded an alarm in March: “Terrorist use of nuclear weapons may not be a high probability—but the global economic, political, and social consequences would be so severe that even a low probability should be enough to motivate an intense focus on steps such as nuclear security to reduce the risk.”

Myth No. 4
The United States is not modernizing its nuclear forces like Russia and other countries are.

Russia has “a much newer capability than we do,” Trump said of America’s nuclear arsenal during Monday’s debate, adding that “we have not been updating” and “we are not keeping up with other countries.”

This is not true. There are nine nuclear-armed nations Israel has not acknowledged its arsenal but is alleged to have 80 warheads and each one is modernizing its nuclear forces in some fashion. North Korea is testing missiles that could deliver a warhead to the United States. China, India and Pakistan are actually enlarging their arsenals. Russia and the United States have embarked on major modernization plans of their nuclear triad: the aircraft, submarines and missiles that launch or carry warheads to their target.

Russia did start its modernization effort earlier than the United States, but that’s because Russia builds warheads and delivery systems that don’t last as long as their U.S. counterparts, says Kingston Reif, director for disarmament and threat reduction policy at the Arms Control Association. Washington’s current and planned investment in nuclear forces is unrivaled, and is estimated to cost $1 trillion over the next 30 years, according to the James Martin Center for Nonproliferation Studies.

“No U.S. military commander would trade the U.S. nuclear arsenal for Russia’s,” Reif says.

Myth No. 5
Nuclear proliferation can only continue.

During a CNN town hall in March, Trump suggested that “it’s only a question of time” before countries like Japan, South Korea and Saudi Arabia obtain nuclear weapons. Trump’s position is that since “so many countries” already have nuclear weapons, it’s more or less impossible to turn back their spread.

Yes, the number of countries with nuclear arsenals has grown over time, but the volume of warheads has been slashed over the past 30 years through intense negotiation by diplomats and hard work by nonproliferation experts. There are around 15,000 nuclear warheads on the planet right now, down from a historical peak of 60,000-plus in the mid-1980s. Material for nuclear weapons has been eliminated from 30 countries. An entire category of nuclear weapon was banned by a 1987 treaty signed by Ronald Reagan and Mikhail Gorbachev. After the dissolution of the USSR, Russians and Americans worked together to secure and dispose of loose fissile material and warheads. Last year’s Iran deal has at least delayed the entry of a 10th member into the nuclear club. Last week, the Obama administration backed a UN resolution that reaffirms the ban on nuclear tests a move to badger North Korea back into compliance.

So progress is possible. Obama, though, has eliminated fewer warheads than his three predecessors did. This slowdown in disarmament, coupled with nuclear modernization plans, has spurred activists and nations to advocate for a new treaty to ban nukes outright. Just this past Wednesday, six countries submitted a resolution to the UN that calls for the negotiation of a ban treaty next year an attempt to turbocharge nonproliferation.

As you might guess, the U.S. government — whose nuclear arsenal is the bedrock of its national security policy — is not in favor of the ban, viewing it as both unrealistic and potentially harmful to the long, grinding process of disarmament. As Secretary Carter said Sept. 7 in Oxford: “We’re going to have nuclear weapons as far into the future as I can see.”


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