This Stanford news release describes research by CISAC's Scott Sagan on American public opinion toward the use of nuclear weapons during wartime. He found that views on nuclear weapons usage has not fundamentally changed since 1945, and many people would support the use of such weapons to kill millions of civilians if the U.S. found itself in a similar wartime situation. Sagan and his co-author used a survey experiment to recreate the situation that the United States faced in 1945 in the Hiroshima nuclear bombing with a hypothetical American war with Iran today.

The results showed little support for the so-called “nuclear taboo” thesis, or that the principle of “noncombatant immunity” – civilian protection from such weapons – has become a deeply held norm in America. The conclusions are stark and disturbing, Sagan said.

“These findings highlight the limited extent to which the U.S. public has accepted the principles of just war doctrine and suggest that public opinion is unlikely to be a serious constraint on any president contemplating the use of nuclear weapons in the crucible of war,” wrote Sagan and his co-author, Benjamin Valentino, a Dartmouth College professor of government.

This story by Elisabeth Eaves in The Bulletin of Atomic Scientists includes an interview with CISAC's Siegfried Hecker on the North Korea situation: 

In July, North Korea tested its longest-range ballistic missiles yet, putting it closer than ever to having a nuclear weapon that could strike the US mainland. But that is not actually our most urgent problem, says Siegfried S. Hecker, a former director of the Los Alamos National Laboratory, who has visited North Korea seven times and toured its nuclear facilities. While North Korea is bent on extending its nuclear strike range, it can already hit Japan and South Korea. With US politicians calling for military action against the North, and a general escalation of belligerent rhetoric on both sides, it is entirely possible that we will stumble into a nuclear war on the Korean peninsula. In this in-depth interview, Hecker calls on Washington to talk to Pyongyang—not to negotiate or make concessions, but to avert disaster. 

BAS: North Korea tested 24 missiles in 2016 and has tested nearly 20 so far this year. What is distinctive about the two it tested in July?

SH: The missile tests on July 4th and 28th were the first that had intercontinental ballistic missile (ICBM) capabilities. They were intentionally launched at lofted angles, most likely so they wouldn’t overfly Japan. According to the Korean Central News Agency, North Korea’s state news outlet, the most recent Hwasong-14 missile reached an altitude of 3,725 kilometers (2,315 miles) and flew a distance of 998 kilometers (620 miles) for 47 minutes before landing in the water off the Korean peninsula's east coast, close to Japan. If launched on a maximum-range trajectory the missile could travel more than 10,000 kilometers (6,200 miles), giving it the ability to reach much of the US mainland. 

BAS: Do these test launches indicate that North Korea has mastered ICBMs?

SH: I think not yet, but these two tests demonstrate substantial progress and most likely mean they will be able to master the technology in the next year or two. The North Koreans have very cleverly combined various missile stages and rocket engines to get this far, but a reliable, accurate ICBM will require more testing. In addition, it is not clear whether they have sufficiently mastered reentry vehicles, which are needed to house the nuclear warhead on an ICBM. Advanced reentry vehicles and mechanisms to defeat missile defense systems may still be five or so years away. However, make no mistake, North Korea is working in all of these directions. 

BAS: Why are intercontinental ballistic missiles—ICBMs—so important, from North Korea’s point of view? 

SH: Pyongyang’s fears of US military intervention have surely grown with the dire warnings coming from US political leaders during the past several months. Pyongyang is determined to develop an effective deterrent to keep the United States out. It apparently views being able to threaten the US mainland with a nuclear counterstrike as the ultimate deterrent. It also likely has a political goal, to get Washington to the table on what Pyongyang would see as a more equal basis. 

BAS: We last spoke in May about North Korea’s nuclear capabilities and the technical challenges it faces—among them, making a nuclear warhead small enough to fit on a missile, and a weapon that can survive the extreme conditions involved during launch, flight, and re-entry into the atmosphere. Have North Korea’s technical capabilities changed since then?

SH: I think the warhead is still the least developed part of North Korea’s plans for nuclear ICBMs. It must survive such extreme conditions, and it must detonate above the target by design. It can’t accidentally detonate on launch or burn up during reentry. North Korea likely made some of the key measurements required to define those extreme conditions during the two July tests, but I can’t imagine it has learned enough to confidently make a warhead that is small and light enough and sufficiently robust to survive. 

Achieving these goals is very demanding and takes time, particularly because warheads contain materials such as plutonium, highly enriched uranium, high explosives, and the like. These are not your ordinary industrial materials. 

BAS: Does North Korea have sufficient plutonium or highly enriched uranium to serve as fuel for nuclear weapons?

SH: This is one of its greatest limitations. It has very little plutonium and likely not yet a large amount of highly enriched uranium. For plutonium particularly, its small 20-to-40 kilogram inventory must be shared among several purposes: experiments required to understand the world’s most complex element, nuclear tests to certify the weapon’s design, and stock for the arsenal. To put North Korea’s plutonium inventory in perspective, the Soviet Union and United States at one time had inventories in excess of 100,000 kilograms each, and China is believed to have an inventory of roughly 2,000 kilograms. Estimates of North Korea’s highly enriched uranium inventory are highly uncertain, but are likely in the 200 to 450 kilogram range, which, combined with its plutonium inventory, may be sufficient for 20 to 25 nuclear weapons. 

Moreover, North Korea has conducted only five nuclear tests and we do not know if these used plutonium or highly enriched uranium for bomb fuel. During one of my seven visits to North Korea, the scientific director of their nuclear center told me that the first two devices used plutonium. During my last visit in November 2010, I was shown a modern centrifuge facility that had just begun operation. Based on that visit, I believe that North Korea most likely also used plutonium for the February 2013 test, but may have used highly enriched uranium for the two tests in 2016. 

Plutonium is a better bomb fuel, although its temperamental properties make it difficult to use reliably. Nevertheless, it would be preferred for making a weapon small enough to mount on an ICBM. Highly enriched uranium is more forgiving from an engineering point of view, but it is more difficult to miniaturize the warhead. North Korea has much more experience in uranium metallurgy than plutonium metallurgy because natural uranium metal is used to fuel its nuclear reactor. However, their overall experience with both materials in nuclear warheads is very limited.

BAS: In May you said you thought five nuclear tests spaced over ten years has likely allowed North Korea to miniaturize a nuclear warhead. Is that at odds with what you now believe?

SH: No. I was then referring to miniaturizing warheads for shorter-range missiles that could reach all of South Korea and Japan. The shorter range allows for much bigger warhead payloads and poses fewer challenges. Uranium could more easily be used for bomb fuel in such warheads. North Korea had no ICBM rocket experience until the two tests in July. Now we are talking about ICBMs, which have much more stringent warhead requirements. Miniaturizing a warhead sufficiently to fit on an ICBM will take more time and tests. 

BAS: Last week, US Secretary of State Rex Tillerson called for discussions with North Korea, although the State Department then appeared to walk back the call for unconditional dialogue. You’ve expressed that dialogue is essential. Why now, and what do you think it could accomplish?

SH: There is an urgent reason to talk to Pyongyang now: to avoid a nuclear conflict on the Korean Peninsula. The greatest North Korean threat we face is not from a nuclear-tipped missile hitting the US mainland, but from Washington stumbling into an inadvertent nuclear war on the Korean peninsula. US Senator Lindsey Graham said last week, “There is a military option: to destroy North Korea’s nuclear program and North Korea itself. He’s not going to allow—President Trump—the ability of this madman [Kim Jong-un] to have a missile that could hit America.” 

I do not think that North Korean leader Kim Jong-un is a madman. We can’t even call him unpredictable any more—he says he will launch missiles, then he does. The madman rhetoric only flames the panic we see in this country because it makes Kim Jong-un appear undeterrable, and I don’t believe that to be the case. He is not suicidal. Nevertheless, it is possible that in his drive to reach the US mainland to achieve a greater balance with the United States, Kim could miscalculate where the line actually is and trigger a response from Washington that could lead to war. The problem is that we know nothing about Kim Jong-un and the military leaders that control his arsenal. It’s time to talk and find out. 

BAS: Both Senator Graham and former State Department official John Bolton spoke of pursuing a military option against North Korea last week. In May you said war would be a disaster. Why is it still being considered an option?

SH: Talk of war is dangerous and irresponsible. It would have catastrophic consequences for Northeast Asia and the world. Military action could slow the North’s program, but not eliminate it. Threats of war, moreover, only make the North redouble efforts to hold the United States at risk. And they greatly exacerbate the greatest risk of all: an inadvertent war on the Korean peninsula with the potential for hundreds of thousands of deaths, including thousands of American citizens. Unfortunately, some American leaders believe that if there is a war, keeping it on the Korean peninsula will keep us safe. I maintain that a nuclear war anywhere will have catastrophic consequences for America. 

BAS: Can you tell us more about what you think dialogue should look like? How do you convince skeptics who think there should be no negotiating with such a belligerent power?

SH: The crisis on the Korean peninsula is so urgent that President Trump should send a small team of senior military and diplomatic leaders to talk to Pyongyang. They must try to come to a common understanding that a nuclear war will inflict unacceptable damage to both sides, so must not be fought, and that a conventional conflict would pose a high risk of escalating to a nuclear war, so must likewise not be fought. 

This sort of dialogue might resemble the one between US President Dwight Eisenhower and Soviet leader Nikita Khrushchev in Geneva in 1955, which US President Ronald Reagan and Soviet leader Mikhail Gorbachev re-affirmed at a Geneva summit in 1985. They agreed that a nuclear war cannot be won, so a nuclear war must not be fought.

The United States and Soviet Union deterred each other through mutually assured destruction. A similar state is achievable with regard to North Korea. Joint US-South Korean conventional forces combined with overwhelming US nuclear forces can assure the North’s destruction. Pyongyang’s nuclear arsenal combined with its conventional artillery and chemical weapons can inflict unacceptable damage to South Korea, Japan, and regional US assets. Although the tradeoff is asymmetric—that is, assured annihilation versus unacceptable damage—I believe it will deter both sides from military aggression. 

BAS: So are you recommending negotiations?

SH: No, the time is not yet ripe for renewed negotiations. Talking is not a reward or a concession to Pyongyang and should not be construed as signaling acceptance of a nuclear-armed North Korea. Talking is a necessary step to re-establishing critical links of communication to avoid a nuclear catastrophe. We must first come to the basic understanding that a nuclear conflict must be avoided. The need to communicate is sufficiently urgent that talks must start without preconditions. 

BAS: What else could talks accomplish?

SH: They would provide an opportunity to impress upon Pyongyang that ensuring the safety and security of nuclear weapons is an awesome responsibility. These two issues are becoming more challenging as Pyongyang strives to make its nuclear arsenal more combat-ready. A nuclear-weapon accident in the North would be disastrous, as would a struggle to control the North’s nuclear weapons in the case of attempted regime change from within or without. 

The talks should also cover the need for mechanisms to avoid misunderstanding, miscalculation, or misinterpretation of actions that could lead to conflict and potential escalation to the nuclear level. In simplest terms, Washington should convey that it is deterred from attacking the North, but not from defending the United States or its allies. It should reiterate that any attack on South Korea or Japan, be it with conventional, chemical, or nuclear weapons, will bring a devastating retaliatory response upon North Korea.

The US delegation could also reinforce Secretary of State Tillerson’s message, that the United States is not aiming to threaten or replace the North Korea regime and is prepared to assure the security it seeks. 

Also, the talks should underline to Pyongyang that any export of nuclear technologies or weapons know-how is unacceptable, and that Pyongyang should not imagine such exports or transfers can be hidden. 

Finally, talks should emphasize that these are talks, not negotiations. The exchange may lay the foundation for a return to diplomatic dialogue on denuclearization and normalization, particularly if Washington listens as well as talks. But that is not what this initial contact should be.

BAS: But won’t any talks be construed as Washington having blinked first and recognized North Korea as a nuclear-armed state?

SH: Washington can acknowledge that Pyongyang possesses nuclear weapons—which is the reality—while also reiterating that it will not accept Pyongyang as a nuclear weapon state. Washington can make clear that it intends to pursue the eventual denuclearization and normalization of the Korean peninsula—goals that North Korea publicly signed on to in 1992, 2000, and 2005. Letting today’s state of affairs persist because we are overly concerned about “blinking” will only make a bad situation more dangerous. 

BAS: The US president has been very critical of China for not doing more to prevent North Korea’s missile and nuclear testing. Is it realistic to think China can control the North’s actions in this way? What do you think the proper role of China is here?

SH: The Obama administration pressured China and it didn’t work. The Trump administration similarly had its hopes pinned on China to pressure Pyongyang, and it won’t work either. We need to understand China’s national interest: It does not want to see Pyongyang armed with nuclear weapons, but it is not willing to bring the regime to its knees to stop it. Quite frankly, Beijing views Washington’s belligerence toward North Korea as the main driver of Pyongyang’s accelerating nuclear weapon program. 

Nevertheless, on Saturday, the two July ICBM launches prompted China to back the most stringent UN Security Council sanctions to date. Chinese state media followed with a statement that said North Korea had to be punished for its missile tests—although on Monday it said the United States must reign in its "moral arrogance over North Korea.”

BAS: What do you fear could happen in the near future if we stay on the current track? Basically, what about this whole situation most keeps you up at night? 

SH: That North Korea continues to make its nuclear arsenal more combat-ready and threatening to the US mainland, and that Washington declares this behavior a red line. And that the provocative rhetoric on both sides fuels more misunderstandings and miscalculations, which trigger a nuclear war on the Korean peninsula.

In this podcast with the Carnegie Council, CISAC's Scott Sagan says that major changes must be made if U.S. nuclear war plans are to conform to the principles of just war doctrine and the law of armed conflict. He proposes a new doctrine: "the nuclear necessity principle." In sum, the U.S. will not use nuclear weapons against any target that could be reliably destroyed by conventional means.

In 2016, Sagan co-authored an op-ed in The Washington Post on this topic: "It is time to turn nuclear common sense into national policy. A declaration that the United States would never use nuclear weapons when conventional weapons could destroy the target could reduce the number of nuclear weapons we need for legitimate deterrence purposes. Placing conventional weapons at the center of debates about the future of deterrence would also help focus the policy discussion on plausible scenarios with realistic plans for the use of U.S. military power. And it would more faithfully honor the just-war principles of distinction, necessity and proportionality, by placing them at the heart of our deterrence and security policies, where our highest ideals belong."

Sergio Rebeles, the first student to graduate with a Global Studies minor in European Studies, received his B.S. in Biology in June.

One of Sergio's earliest impetuses towards a global focus for his education was becoming aware of the Sinjar massacre of Yazidis in northern Iraq in 2014. At Stanford, Sergio's native Spanish-speaking abilities led him to volunteer as a medical Spanish Interpreter at free clinics at Stanford and in San Jose. This solidified his desire to attend medical school in the future.

Sergio's interest in international affairs led him to study abroad with Stanford's Bing Overseas Studies Program in Madrid and Paris. After considering both the French and International Relations minors, Sergio ultimately chose the European Studies minor because of its "flexibility and interdisciplinary/comparative focus." Sergio's favorite class of those specifically taken for the minor was History of the International System (INTNLREL 102), taught by Norman Naimark.

In Madrid, Sergio interned at a Catholic school where he gave English lessons to first graders. In France he enjoyed a French art history class that included trips to the Louvre and Musee d'Orsay. While abroad he also "treasured the time I spent with my host family, which included two young boys, and thus very stimulating dinners."

Sergio is confident that studying both science and the humanities at Stanford helped to make him a well-rounded graduate. "There’s certainly a difference in personality type between the ‘hard’ and ‘soft’ sciences, and it was refreshing to experience both during my time on the Farm. Believe it or not, I would even describe it as cathartic to work on an essay between bouts of memorizing biochemical pathways or practicing genetic crosses."

Sergio's one regret is that, because the minor program was new, he was not able to take the introductory courses (Global 101 and International Relations 122) before his study abroad, and he found that what he learned in them would have been useful in framing his European experience. In planning his studies, Sergio appreciated the guidance of advisors Ken Scheve, director of The Europe Center (TEC), and Christophe Crombez.

Sergio's immediate plans include studying for the MCAT and working for two years as a high school math teacher in Miami for Teach For America. We wish him the best of luck in his future endeavors!

Learn more about the Global Studies Minor with a Specialization in European Studies.

Published in the journal Bulletin of Atomic Scientists, this new article by Siegfried Hecker and Paul C. White below is based on content in Hecker's 2016 book, Doomed to Cooperate: How American and Russian Scientists Joined Forces to Avert Some of the Greatest Post-Cold War Nuclear Dangers:

“Nuclear weapons stink when taken apart,” a Russian nuclear weapons engineer told his audience. The year was 2000, and he spoke to a group of Russian and American experts who were attending a workshop in Sarov, the Russian Los Alamos, on how to safely dismantle nuclear weapons. The engineer was right: Nuclear weapons being disassembled smell like rotten eggs or a high-school chemistry lab gone bad. They can contain high explosives, organic substances, uranium, plutonium, and many other materials. Over the years, these materials interact, outgas, corrode, and are subject to irradiation, producing a foul smell. Hardly anyone outside the room would have had any reason to be aware of this, so the engineer’s words inspired knowing nods, and acted like a wink or a secret handshake: The Russian and American nuclear scientists in the room shared a common bond.

It was a strange phenomenon. Until just 10 years previously, the experts’ respective governments had been adversaries. But Russian and American nuclear scientists shared ties that no one else in the world could appreciate. Working far apart, they and their forebears had ushered into existence the world’s most destructive weapon, the atom bomb. They had worked to improve it, manage it, and make sure it was reliable. Now, they were trying to keep nuclear weapons safe from accidents and secure against theft and sabotage as the two superpowers downsized their arsenals. The scientists and engineers knew something that few others understood: That the most dangerous time in a typical nuclear weapon’s life cycle is not when it is being created, transported, or readied for launch. Rather, it is when it is being taken apart. Corrosion, changes in the sensitivity of chemical high explosives, outgassing of various compounds, radiation damage, and dimensional changes all challenge the skills of weapons engineers and scientists. The experts in the room might once have been one another’s opponents in some sense, but many on each side had intimate knowledge of weapons disassembly—who else could better understand what their counterparts were going through? 

An urgent problem

The story of how the United States and Russia worked together to address weapons safety had begun years before, and represents a remarkable tale of once-mortal-adversaries cooperating on matters that took them right to the edges of their respective countries’ most sensitive nuclear secrets.

It started with the disastrous Chernobyl nuclear reactor accident in April 1986. After briefly denying it had occurred, Moscow reached out to the international nuclear community for help mitigating the tragic consequences. Washington assisted quickly and effectively. Years later, Russian nuclear weapon scientists told their American counterparts (including the authors of this column) that the Chernobyl accident had happened because the Soviet Union was isolated. That is, Russian nuclear reactor designers, engineers, and operators had not had the opportunity to learn from their international peers. The weapon scientists assured us that the safety of nuclear bombs had always been much more rigorous. Yet the memory of the Chernobyl tragedy, and the enormous increase in the number of weapons being moved and disassembled, made Russian nuclear scientists keen to discuss concerns and safety practices with American counterparts.

The end of the Cold War all but eliminated immediate fears of a nuclear war. In an ironic twist of fate, though, it dramatically increased the risk of nuclear accidents and the potential for theft or diversion of nuclear weapons and materials. When the Soviet Union collapsed, Russia had to transport unprecedented numbers of weapons from former Soviet republics to Russia for dismantlement. No one was as sharply aware of the risks as Russia’s nuclear weapons personnel.

In the wake of the Presidential Nuclear Initiatives launched by George H.W. Bush and Mikhail S. Gorbachev in September and October of 1991, which promised transparency and dialogue on safe warhead transportation and storage, the Russians gave voice to their concerns. In Washington in November 1991, Viktor N. Mikhailov, later Russia’s minister of atomic energy, specifically requested help with weapon safety and security, as well as help storing the huge excess of fissile material that would result from the accelerated dismantlement of his country’s nuclear stockpile. The US Congress responded to these requests promptly by way of the Nunn-Lugar cooperative threat reduction legislation.

The scope and timing of the Nunn-Lugar efforts matched the urgency of Russian requests. To deal with security concerns related to the surge in warhead transportation, the United States cooperated to develop accident-resistant transportation containers. It provided armored Kevlar blankets to shield warheads and warhead containers from terrorist bullets, and smart rail cars that enabled secure monitoring of warhead shipments. Washington also helped meet the new storage requirements (resulting from increased dismantlement rates) by providing containers and technical and financial support for the construction of a state-of-the-art fissile material storage facility at the Mayak site in Russia.

These Nunn-Lugar-sponsored efforts, managed by the US Defense Department and supported by the US national nuclear labs, were a good beginning, but the Russian nuclear weapons experts wanted to do more to mitigate the dangers. The extraordinary number of nuclear weapons returning from the field and waiting to be disassembled included some past their certified lifetime. During one of the first meetings of Russian and American nuclear experts at Los Alamos in December 1992, Rady I. Ilkaev, the deputy scientific director of the Russian national nuclear lab VNIIEF, proposed direct, unclassified consultations on nuclear weapon safety.

The Russians not only sought bilateral technical cooperation, but also believed that Russian-American teamwork would demonstrate an unparalleled level of transparency about nuclear safety, which would help reassure their own citizens and a worried world that remembered the Chernobyl tragedy all too well.

Ilkaev and his Russian colleagues took advantage of the lab-to-lab scientific collaborations that blossomed during the early 1990s to explore much closer cooperation on safety—an approach that resonated strongly with their US lab counterparts. Yet no government agreements were in place to allow such cooperation. So two tracks were pursued in parallel: The governments prepared for formal negotiations, while simultaneously allowing the labs to exchange sensitive but unclassified nuclear-weapon safety and security concerns and practices. This sharing took the form of symposia called the Security Technology Exchanges. 

Four such symposia were held between October 1993 and March 1994, two in each country, at which American and Russian scientists, engineers, and government officials compared experiences on a range of topics. Subjects included analyzing nuclear risk; mitigating risks posed by hazardous materials; understanding the response of engineered systems to abnormal environments; and communicating the content of technical documents. 

One of the most important topics discussed in these symposia and later exchanges was human reliability. The economic and political crisis resulting from the collapse of the Soviet Union severely strained one of the foundations of nuclear weapon safety: people. One of the authors of this piece (Paul C. White) recalls that at a July 1993 planning meeting in Ekaterinburg, his Russian counterpart asked, “What do you do when you can no longer count on people to do what they’re supposed to do—to obey the rules?” Although the Russians’ confidence in the loyalty and patriotism of their nuclear workers remained high, they expressed concern that the fraying of the decades-old system of authority could give rise to insider threats.

A mutual strategic interest

These symposia opened doors, established a foundation for building trust, and nurtured professional and personal friendships that endure to this day. They also helped pave the way for government negotiations on the Weapons Safety and Security Exchange agreement, or WSSX, which the US energy secretary and Russian minister of atomic energy signed in December 1994. It entered into force in June 1995. 

In a March 1996 directive, US President Bill Clinton stated that cooperation on weapons safety and security was necessary to facilitate other US policy objectives, such as getting Russia to agree and comply with a true zero-yield Comprehensive Nuclear Test Ban Treaty. Clinton authorized lab-to-lab collaboration between the three Russian and three US nuclear weapons labs, with the goal of sustaining the scientific competence of those responsible for the two countries’ respective nuclear stockpiles. His statement was remarkable for declaring that maintaining the expertise of Russian nuclear weapons scientists—America’s Cold War adversaries—was now a US strategic interest.

Although WSSX was an agreement between governments, the nuclear labs provided the driving energy and remained the centers of engagement for all related activities. Over the life of the agreement, which was renewed for five years in 2000, the two sides organized dozens of technical interactions, including symposia, joint studies, workshops, and exchanges of technical papers. The participants completed more than 100 collaborative projects on far-reaching and mutually beneficial topics. Among them were projects on accident response, responding to wildfires near nuclear facilities, and safety during warhead dismantlement. When Americans shared their experience of using a well-known industrial solvent—DMSO, or dimethyl sulfoxide—instead of mechanical methods to remove high explosives that had bonded to metal weapon parts, a Russian participant stood up and declared, “you have just given us a gift!” Such “gifts” were exchanged reciprocally to improve warhead disassembly on both sides.

The discussions on responding to wildfires would also prove mutually beneficial. It wasn’t just technical staff from Los Alamos and Sarov who got to participate in exchange visits. So, too, did the fire departments of the two cities. In May 2000, Los Alamos experienced a devastating fire that burned more than 400 residences and 30 percent of the lab’s real estate, and threatened facilities that housed high explosives, plutonium, and tritium. In 2010, Sarov had to battle a peat fire at the boundary of its nuclear complex. Los Alamos experienced another serious wildfire in 2011. 

The WSSX exchanges allowed experts to learn new ways of looking at similar problems, unquestionably benefiting each country’s handling of the safety and security of its nuclear weaponry. In the book Doomed to Cooperate, one Russian nuclear safety expert said the exchanges led his country to adopt new federal regulations on nuclear weapons safety and emergency response. 

Sadly, the WSSX agreement was not extended in 2005. The end of this remarkable period of cooperation came at the hands of governments, not scientists. Washington imposed more legal and bureaucratic strictures on joint projects, and veered away from prioritizing nuclear safety to promote an agenda of arms control and transparency. Moscow became increasingly resistant to the presence of US technical personnel at its nuclear facilities. During the last three years, as relations between the US and Russian governments have seriously deteriorated, virtually all nuclear cooperation has ended.

Nuclear safety has become more challenging as the designers and engineers who developed the weapons in today’s arsenals retire, and the experience of nuclear testing fades into distant memory. The older generation has passed on as much experience as possible to the younger engineers—particularly the idea that ensuring nuclear safety is a never-ending job. The WSSX projects demonstrated that cooperation has great safety benefits, and can be accomplished without jeopardizing either side’s nuclear secrets. The scientists and engineers on both sides are prepared to resume cooperation. The bonds they forged endure, reflecting a unique like-mindedness, a sort of simpatico professional relationship (or sympatiya in Russian) that helped make scientific engagement such a success and the world a safer place.