This is the eighth and last in a series of interviews by the Korea Times on North Korea. CISAC's Siegfried Hecker is featured in this story below by Kim Jae-kyoung:

NK estimated to have ability to produce 7 nuclear bombs a year

By Kim Jae-kyoung

A world-renowned nuclear scientist said that U.S. President Donald Trump must to talk to North Korean leader Kim Jong-un by sending an envoy to Pyongyang to avoid a nuclear catastrophe.

"I believe the first talks should be bilateral and informal by a presidential envoy talking directly to Kim Jong-un," said Siegfried S. Hecker, a senior fellow at the Center for International Security and Cooperation (CISAC) at Stanford University, in an interview.

"I believe both Seoul and Beijing would support such talks. These talks may then also help to build the foundation for renewed multilateral negotiations, which, first and foremost must involve South Korea, as well as China," he added.

Hecker, the co-director of CISAC from 2007 to 2012, has visited North Korea several times to assess the plutonium program at the Yongbyon Nuclear Scientific Research Center since 2004.

He stressed that it is most important to convey the message that nuclear weapons cannot be used under any circumstances.

"There is no such thing as a limited nuclear war. Any explosion of a nuclear device on the Korean Peninsula is a catastrophe of indescribable proportions," he said.

The internationally recognized expert in plutonium science, global threat reduction and nuclear security said that the Trump administration and the new South Korean government face the challenge of avoiding a nuclear detonation on the Korean Peninsula.

He believes that such an incident could result from a miscalculation or overconfidence by the Kim Jong-un regime as well as an accident with the nuclear weapons in the North.

"A conventional confrontation may turn nuclear with an inexperienced leader in charge," he said. "Or, in the case of instability in the North, who will control the nuclear weapons? These are serious concerns that must be addressed now," he added.

Hecker, who served as the director of the Los Alamos weapons laboratory in New Mexico, the birthplace of the atomic bomb, from 1986 to 1997, estimated that North Korea, although he is uncertain, may have sufficient material for 20 to 25 nuclear weapons.

NK's nuclear capabilities evolving 

He explained that the size of its nuclear arsenal depends primarily on how much plutonium and highly enriched uranium North Korea has produced.

"The sophistication of the arsenal depends primarily on nuclear testing. With five nuclear tests conducted over 10 years, North Korea is likely able to produce nuclear devices small enough to fit on missiles that can reach all of South Korea and Japan," he said.

He also estimated that the totalitarian country can produce sufficient plutonium and highly enriched uranium for six to seven bombs per year.

"However, all estimates are uncertain because we know little about the North's capacity to produce highly enriched uranium since it is not possible to monitor such facilities from afar," he said.

In his view, the world does not have to accept the reclusive country as a "nuclear weapons state," but it must be treated as a country with a nuclear arsenal.

"Whether we like it or not, North Korea is a country with nuclear weapons," he said. "The final aim is to have a denuclearized Korean Peninsula, but that will take time. It will have to be done in sequence of halt, roll back and then eliminate."

However, Hecker dismissed North Korea's claim that it has the capability to fire an intercontinental ballistic missile (ICBM) all the way to the U.S. mainland.

"I do not believe North Korea is capable of reaching the U.S. mainland with a nuclear-tipped missile today. It is working on developing such a capability, but it will likely take another five years or so," he said.

Hecker explained that it has not demonstrated all the aspects of necessary rocket technology or the ability to make a nuclear warhead small enough to be able to survive atmospheric reentry.

"Besides, to actually launch a nuclear warhead on an ICBM you must have complete confidence that it will not blow up on the launch pad," he added. "They cannot have such confidence based on their missile launch history."

After the 2012 mass shooting of children and teachers at Sandy Hook Elementary School in Connecticut, a leader of the National Rifle Association proclaimed: “The only thing that stops a bad guy with a gun is a good guy with a gun.”

It would seem that many Californians agreed, according to new research by Stanford Health Policy’s David Studdert and other researchers at academic institutions.

In the six weeks after the Newtown shootings — when a young man fatally gunned down 20 children and six adults — handgun acquisitions in California rose by 53 percent among first-time gun owners over expected levels.

When a couple armed with semi-automatic weapons targeted a San Bernardino County public health event in December 2015, killing 14 people in 2015, handgun purchase rates were 85 percent higher than expected among residents of the city of San Bernardino and adjacent neighborhoods, compared with 35 percent higher elsewhere in California.

In a new study in the Annals of Internal Medicine, lead author Studdert, a professor of medicine at Stanford Medicine and professor of law at Stanford Law School, writes that their findings have implications for public health as firearm ownership is a risk factor for firearm-related suicide and homicide.

“There is strong evidence linking gun ownership to risks of gunshot injuries, so any sudden boost in firearm ownership could have public health implications,” Studdert said. On their own, these two mass shootings are unlikely to have caused enough of a change in ownership patterns to have significant public health effects.

“But over time, purchasing responses to a succession of unnerving events like this — from mass shootings to terrorist attacks, to elections — could change levels of gun ownership enough to increase overall rates of gun injury and death.”

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The authors write that for some, mass shootings may induce repulsion at the idea of owning a weapon. But for others, they note, it may motivate acquisition.

“Mass shootings are likely to boost sales if they heighten concerns over personal security because self-protection is the most commonly cited reason for owning a firearm,” they said.

More than 32,000 people die of gunshot wounds in the United States each year, according to the Centers for Disease Control and Prevention. While mass shootings account for less than 1 percent of those deaths, they are the most visible form of firearm violence because of the extensive broadcast and social media coverage that surround them.

Using detailed individual-level information on firearm transactions in California between 2007 and 2016, the researchers analyzed acquisition patterns after two of the highest-profile mass shootings in U.S. history. They found large and significant spikes occurred among whites and Hispanics, and among individuals who had no record of having previously acquired a handgun.

Although these spikes in handgun purchases after both mass shootings were large, they were also short-lived and accounted for less than 10 percent of annual handgun purchases statewide.

“Concerns about firearm violence and the public health risks of firearm ownership should stay focused on the much larger volume of weapons that routinely changes hands, and the immense stock that already sits in households,” write Studdert and his colleagues, Stanford Health Policy researcher Yifan Zhang, PhD; Jonathan Rodden, PhD, a professor of political science at Stanford; Rob J. Hyndman, PhD, a professor of statistics at Monash University in Australia; and Garen J. Wintemute, MD, MPH, an expert on gun violence at the University of California, Davis.

“On the other hand, the cumulative effect of such ‘shocks’ as Newtown and San Bernardino shootings on firearm prevalence may be substantial,” they write. “Moreover, firearm acquisitions seem to be sensitive to a range of other events that are also common, such as federal elections, new firearm safety laws, and terrorist attacks.”

Taken as a whole, they said, these events may drive significant increases in overall firearm prevalence, which may, in turn, increase the risk for firearm-related morbidity and mortality in the long run. The authors urge further research should explore the cumulative effects and temporary shifts in acquisition patterns, their causes, and their implications for public health, crime and social cohesion.

When one thinks of the casualties of war, it is easy to imagine severed limbs, bullet holes, shrapnel, perhaps even sarin gas or Agent Orange. But in a recent Daedalus essay, Paul Wise argues that the most damaging health impacts of war are often indirect. Losing access to food supplies, medication and electricity can kill more people than battle itself. In this video by the American Academy of Arts and Sciences, Wise, a professor of pediatrics and Stanford Health Policy core faculty member, explains how fatal the indirect costs of war can be.

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While the United States has no peers in conventional military power, it is especially vulnerable – as a free and democratic society – to cyber misinformation campaigns, a Stanford scholar says.

Herbert Lin, a senior research scholar for cyberpolicy and security at Stanford’s Center for International Security and Cooperation (CISAC), is the co-author of a new draft working paper that spells out the perilous risks facing democratic, wired-up countries around the world.

America’s adversaries are seeking “asymmetric” methods for social disruption, rather than direct military conflict, Lin said.

“Cyber warfare is one asymmetric counter to Western (and especially U.S.) military advantages that depend on the use of cyberspace,” wrote Lin and his co-author Jackie Kerr, a research fellow at the Lawrence Livermore National Laboratory.

This new type of cyber aggression is aimed at winning – and confusing – hearts and minds, the very control centers of human existence, Lin said.

As a result, “information/influence warfare and manipulation,” or IIWAM as Lin describes it, poses profound implications for Western democracies, even though much of it may not be illegal under international law. This approach is based on the deliberate use of information by one party on an adversary to confuse, mislead, and ultimately to influence the choices and decisions that the adversary makes.

A recent example in point would be the 2016 Russian hacking of the U.S. presidential election and the surge of so-called “fake news.”

Lin points out that while misinformation campaigns are not new, the technology to spread it far and wide globally is. He noted that the patron saint of distorting reality for war-like purposes is Sun Tzu, who wrote that, “The supreme art of war is to subdue the enemy without fighting.”

While traditional cyber attacks typically hit hard targets like computer systems, cyber “influence” campaigns are conducted over longer periods of time and rely on soft power – propaganda, persuasion, culture, social forces, confusion and deception, Lin said. 

Words and images

How does it work? Lin explains:

“Victory is achieved by A when A succeeds changing B’s political goals so that they are aligned with those of A.  But such alignment is not the result of B’s 'capitulation' or B’s loss of the ability to resist – on the contrary, B (the losing side) is openly willing.”  That is, such victory shares the focus on subverting the opponent’s will, though not on destroying his military forces.

The ammunition in these cyberspace battles are “words and images,” the kind that persuade, inform, mislead, and deceive so that the adversary cannot respond militarily. In the example of a “fake news” story, they often take place below legal thresholds of “use of force” or “armed attack,” and at least in an international legal sense, do not trigger a military response.

The target is the “adversary’s perceptions,” which reside in the “cognitive dimension of the information environment.” In other words, such cyber warfare focuses on “damaging knowledge, truth, and confidence, rather than physical or digital artifacts,” according to Lin. It is the “brain-space.”

Additionally, IIWAM injects fear, anger, anxiety, uncertainty, and doubt into the adversary’s decision making processes, he added.  Success is defined as altering such perceptions so the target makes choices favoring the aggressor.

“Sowing chaos and confusion is thus essentially operational preparation of the information battlefield – shaping actions that make the information environment more favorable for actual operations should they become necessary,” the researchers wrote.

These cyber manipulations often prey upon cognitive and emotional biases present in the psychological and mental makeup of human beings, Lin said. 

For example, media channels such as Fox News play to “confirmation bias” for individuals with a right-of-center orientation, and similarly for MSNBC for those with a left-of-center, orientation, he wrote. Confirmation bias is the tendency to interpret new evidence as confirmation of one's existing beliefs or theories.

Countering misinformation

“Naming and shaming” is probably ineffective against many nation states conducting cyber disinformation campaigns, Lin said. And the idea that a government like the U.S. can quickly respond to misinformation created in the private sphere is unlikely to be effective as well.

What, then, might work? Lin suggests new tactics are needed, as no existing approach seems adequate. For example, Facebook is deploying a new protocol for its users to flag questionable news sites.  Google has banned fake news web sites from using its online advertising service. Twitter, YouTube, and Facebook shut down accounts that they determine are promoting terrorist content.  He noted that a recent Facebook letter from CEO Mark Zuckerberg states that, “Our approach will focus less on banning misinformation and more on surfacing additional perspectives and information, including that fact checkers dispute an item's accuracy.”

But such measures are unlikely to stem the “rising tide of misinformation conveyed” through cyber warfare, Lin said, because they mostly require users to do additional mental work.  

Wired world riskier

Today’s Internet-driven Western world offers countless opportunities for cyber influence mischief, Lin wrote.

“Democracy has rested on an underlying foundation of an enlightened, informed populace engaging in rational debate and argument to sort out truth from fiction and half-truth in an attempt to produce the best possible policy and political outcomes,” Lin wrote.

Cyber manipulators have exploited an arguable gap between ideals and reality in democratic systems – “rendered it much more questionable” – through the tremendous reach and speed of misinformation, he said. Many countries cannot deal with the onslaught of such focused efforts. This serves to make the democratic process look weak and unstable in the eyes of its citizens. The same dynamic does not apply equally around the world.

“Cyber weapons pose a greater threat to nations that are more advanced users of information technology than to less-developed nations,” Lin wrote.

He said that less developed or authoritarian countries do not have much Internet infrastructure or that wield control over expression – North Korea is an example.

MEDIA CONTACTS

Herbert Lin, Center for International Security and Cooperation: (650) 497-8600, herbert.s.lin@stanford.edu

Clifton B. Parker, Center for International Security and Cooperation: (650) 725-0224, cbparker@stanford.edu

Anna Péczeli, a Stanton Nuclear Security Fellow at CISAC, wrote the following op-ed for the Bulletin of the Atomic Scientists:

What does the future hold for the US nuclear posture under President Trump? The last Nuclear Posture Review occurred in April 2009, when a 12-month review process was conducted to translate President Obama’s vision into a comprehensive nuclear strategy for the next five to 10 years. The review addressed several major areas: the role of nuclear forces, policy requirements, and objectives to maintain a safe, reliable, and credible deterrence posture; the relationship between deterrence policy, targeting strategy, and arms control objectives; the role of missile defense and conventional forces in determining the role and size of the nuclear arsenal; the size and composition of delivery capabilities; the nuclear weapons complex; and finally the necessary number of active and inactive nuclear weapons stockpiles to meet the requirements of national and military strategies.

Clearly, changes are afoot. On January 27, 2017, President Trump issued a presidential memorandum that mandated “a new Nuclear Posture Review to ensure that the United States nuclear deterrent is modern, robust, flexible, resilient, ready, and appropriately tailored to deter 21st-century threats and reassure our allies.” 

Looking ahead, the new administration should conduct this review through a broad, inter-agency process, involving the State and Energy departments, and allies as well. This approach offers several valuable benefits by broadening the focus from deterrence to non-proliferation, reassurance, and nuclear security.

The main role of the Nuclear Posture Review, or NPR, is to assess the threat environment, outline nuclear deterrence policy and strategy for the next 5 to 10 years, and align the country’s nuclear forces accordingly. Since the end of the Cold War, each administration has conducted its own NPR, but the process and the scope of the reviews were different in all three cases. 

The first NPR was conducted by the Clinton administration in 1994, and even though important senior positions have still not been appointed by the Trump White House, Trump's mandate suggests that their review might use it as a template for 2017. It was a bottom-up review, initiated by the Department of Defense, mostly focusing on a set of force structure decisions—such as the right size and composition of US nuclear forces, including the size of the reserve or so-called “ hedge” force. That review lasted for 10 months, and the Pentagon was in charge of the entire process, mainly focusing on deterrence requirements. 

In contrast, the 2001 NPR of the Bush administration was mandated by Congress, and it addressed a broader set of issues, including all components of the deterrence mix—nuclear and non-nuclear offensive strike systems, active and passive defenses, and the defense infrastructure. The Defense Department took the lead in this case just as before, but this time the Energy Department and the White House were also engaged in the process. As a result, the Bush NPR’s force structure requirements—how to size and sustain the country’s forces—were driven by four factors: assuring allies, deterring aggressors, dissuading competitors, and defeating enemies. 

The Obama administration’s 2010 NPR was also mandated by Congress, but the Defense Department was specifically tasked to conduct an inter-agency review. Besides the unprecedented level of such cooperation, a bipartisan Congressional commission also laid out a number of recommendations for the review process, many of which became part of the final text of the Obama review. Officials from State, Energy, and the Joint Chiefs of Staff were involved, as well as US allies who were regularly briefed during the different stages of the review. 

In the final phase of the 2010 NPR, the White House leadership made the decisions on the actual content of the nuclear posture. While the Clinton and the Bush reviews were largely conducted behind the scenes and only short briefing materials were published on the outcome, the Obama administration released an unprecedentedly long report on its nuclear posture review. 

These cases offer two models for a review process: It can be conducted by a small group of people in the most highly classified manner, or it can be a larger, relatively transparent inter-agency process. In the former approach, the final decisions are typically presented to the secretary of defense, the president, Congress, and allies. The problem is that this tends to be a one-sided approach, putting the main focus on deterrence and modernizations. 

Though it is effective and fast, the implementation of a Nuclear Posture Review requires all stakeholders to be on board with the new strategy. One of the most painful lessons of the Bush review was that because the White House and Defense failed to explain their new approach to the public, the military, and Congress, there was effectively a loss of leadership—which made procurement extremely difficult and caused major problems in the implementation of their strategy. 

On the other hand, involving all stakeholders and providing a balanced approach to nuclear strategy would support the goals of not just deterrence, but those of reassurance, non-proliferation, and nuclear security as well. Due to the involvement of the State Department, the 2010 NPR, for example, emphasized a number of policies which supported non-proliferation objectives and strengthened US negotiating positions at global arms control forums. One of these policies was the “negative security assurance,” which stated that the United States would not use or threaten to use nuclear weapons against non-nuclear weapon states that are party to the NPT and in compliance with their nuclear nonproliferation obligations. 

The other policy that was advocated by senior State Department officials was the so called sole-purpose posture—which means that nuclear weapons only serve to deter or respond to a nuclear attack, and they no longer play a role in non-nuclear scenarios. Although the sole purpose posture was eventually dropped and it was set only as a long-term objective, the Obama administration still reduced the role of nuclear weapons with the new negative security assurance, and it signaled its intent to continue this process with the promise of sole purpose. These steps supported US leadership at the 2010 Nuclear Non-Proliferation Treaty Review Conference and they contributed to the adoption of a consensual final document at the conference. 

This broader scope strengthens inter-agency cooperation, and ensures that all the departments that are affected by the NPR are on board with the strategy, which eases the implementation of the decisions. Besides, it also strengthens alliance relations by regular consultations. The Trump administration’s mandate did not include a specific timeline or format; consequently it will be mainly the responsibility of Defense Secretary James Mattis to decide on the framework. Though the presidential memorandum did not require an inter-agency process, it would be wise to conduct one.

Compared to 2010, the security environment has dramatically deteriorated: renewed tensions between NATO and Russia since the annexation of Crimea, China’s building of military bases in what had previously been international waters, significant military modernization efforts by both these states, and North Korea’s increasingly bellicose nuclear threats. All of these developments have created a serious deterrence and security challenge for the United States and its allies. Only a broader approach can address all relevant threats and create the necessary internal consensus for the funding and creation of a modern, robust, flexible, resilient, ready, and appropriately tailored nuclear arsenal.

Siegfried S. Hecker wrote the following essay for the U.S. News & World Report in an online discussion among seven experts regarding North Korea's nuclear situation:

The North Korean nuclear crisis continues to dominate the news, but it has been remarkably devoid of analysis. To resolve the crisis it is crucial to understand what nuclear capabilities North Korea has, how it acquired them, when and why.

What? A nuclear weapons arsenal requires bomb fuel, the ability to weaponize and the ability to deliver the bomb. Bomb fuel, namely plutonium or highly enriched uranium, is typically the most difficult to acquire. Plutonium is produced in reactors and uranium is enriched in centrifuges. The rate of production of bomb fuel constrains the size of the arsenal.

Siegfried S. Hecker, Center for International Security and Cooperation: (650) 725-6468, shecker@stanford.edu

Clifton B. Parker, Center for International Security and Cooperation: (650) 725-6488, cbparker@stanford.edu

"What is behind democracy’s seeming decline? What is fuelling the widespread appeal of authoritarianism? Is liberal democracy simply a politics of prosperity, but ill-suited for times of crisis and parsimony? By privileging individual choice and minimizing civic virtue, is liberal democracy simply a victim of its own ‘success’?" For ABCRadio, Larry Diamond, Senior Fellow at CDDRL/FSI discusses the dangers of authoritarianism. Listen here. 

Published in the journal Bulletin of Atomic Scientists, this column by Siegfried Hecker is based on content in his 2016 book, Doomed to Cooperate: How American and Russian Scientists Joined Forces to Avert Some of the Greatest Post-Cold War Nuclear Dangers:

The first Russian explosive device to land on US soil wasn’t delivered by a Russian missile, as Americans feared might happen throughout the Cold War. It was delivered by FedEx. The device, an explosive magnetic flux compression generator, arrived at Los Alamos National Laboratory in late 1993, shipped from the Russian Federal Nuclear Center VNIIEF. It allowed Los Alamos and VNIIEF scientists to conduct a groundbreaking joint experiment to study high-temperature superconductivity in ultra-high magnetic fields. 

The shared excitement and jubilation the scientists involved felt over successful experiments like this were testament to a profound shift. Less than two years after the dissolution of the Soviet Union and some 18 months after the remarkable and improbable exchange visits between Russian and American nuclear weapons lab directors, scientists from Los Alamos and VNIIEF were conducting experiments at each other’s previously highly secret sites. Some of these scientists had helped design their country’s hydrogen bombs. Now, they were focused on fundamental scientific discovery. 

The Soviet nuclear weapons program was built on the shoulders of scientific giants—Yuli B. Khariton, Igor V. Kurchatov, Igor E. Tamm, Andrey D. Sakharov, Yakov B. Zeldovich, and many others—just as the American program was built on the shoulders of J. Robert Oppenheimer, Enrico Fermi, Hans Bethe, Edward Teller, John von Neumann, and many more. Unlike their American counterparts, though, Soviet weapons scientists labored in secrecy during the Cold War. When Soviet leader Mikhail Gorbachev lifted the Iron Curtain, curiosity about US research and a pent-up desire to cooperate internationally led them to reach out to the American nuclear weapons labs during the last three years of the USSR. They did so at international conferences and during first-time lab exchanges, long before Washington was prepared for such collaborations. 

Scientific cooperation tapped into the most basic interest of scientists and engineers on both sides, namely, the desire to create new knowledge and technologies. Science is fundamentally an interactive, cooperative pursuit, which requires exposing the results of research to review and critique. As a participant in those early exchanges, I can say that the common language of science allowed us to more easily cross cultures and borders. The two sides’ expertise and facilities proved enormously synergistic, resulting in remarkable progress in several areas of science that neither side alone could have produced for some time to come. We found science, unlike politics, to be a unifying force—one that allowed us to build trust through collaboration.

The pursuit of fusion

High-energy-density physics was the first—and over the years, most intense—area of cooperation between US and Russian nuclear labs. The field involves studying materials at high densities, extreme pressures, and high temperatures, such as those found in stars and the cores of giant planets. On Earth, these conditions are found in nuclear detonations, the basic physics of which were obviously of great interest to the scientists involved. 

Working together, they used VNIIEF explosive magnetic flux compression generators in Russia, VNIIEF generators sent by FedEX from Russia to the United States and charged with US-supplied explosives, and stationary pulsed-power machines at Los Alamos to produce ultra-high electrical currents and magnetic fields that, in turn, produced a wide range of high-energy density environments. This technology provided the capability needed to pursue a unique approach to civilian nuclear fusion, which has tantalized the international physics community for decades with its potential to provide unlimited clean energy. Such energy densities also enabled the scientists to study materials strength under extreme conditions, material behavior under super-strong magnetic fields, and many other problems.

In fact, the initial Los Alamos interest in VNIIEF flux compression technology was stimulated by VNIIEF’s approach to an emerging energy research area now called magnetized target fusion, as Los Alamos scientists I.R. Lindemuth and R. R. Reinovsky and VNIIEF scientist S.F. Garanin write in Doomed to Cooperate. Magnetized target fusion is an approach to fusion that relies on intermediate fuel densities, between the more conventional magnetically confined fusion and inertially confined fusion. 

High-energy-density physics is exciting science that helps attract talent, especially young recruits. It represents a non-military outlet for creative weapon scientists to solve big-world problems for the benefit of mankind. It allows scientists to create new knowledge, not just try to prevent potential new nuclear dangers. It also opened the door to cooperation by scientists with complimentary skills. The Russian side excelled in the design of the explosive generators, the American side in instrumentation and diagnostics, allowing the partnership to go beyond what had been achieved before by either side alone. For example, in the mid-1990s VNIIEF scientists produced a world-record magnetic field of 28 million gauss, some 50 million times larger than the magnetic field at the earth’s surface. Moreover, many of the joint high-field experiments were considered the best-instrumented ever. US-Russian collaborations on high-energy-density physics between 1993 and 2013 resulted in over 400 joint publications and presentations, and opened the door for joint work in other areas. 

An enigmatic element

Plutonium science was similarly of great interest to both sides, yet direct collaboration was not established until the late 1990s because of the sensitivity of the subject. Some fundamental aspects of plutonium science were first presented by Americans and Soviets at the Geneva International Conferences on the Peaceful Uses of Atomic Energy in 1955 and 1958. However, the US and Russian results presented in these and subsequent meetings differed dramatically, and the differences were not resolved until we established direct lab-to-lab collaborations. 

By the early 1990s, both sides had for decades attempted to understand plutonium, a complex metal that exhibits six solid crystallographic phases at ambient pressure. Its phases are notoriously unstable, affected by temperature, pressure, chemical additions, and time (the latter because of the radioactive decay of plutonium). With little provocation, the metal can change its density by as much as 25 percent. It can be as brittle as glass or as malleable as aluminum; it expands when it solidifies, and its freshly machined surface will tarnish in minutes. It challenges our understanding of chemical bonding in heavy element metals, compounds, and complexes. Indeed, plutonium is the most challenging element.

Several of my Russian counterparts and I have devoted much of our 50 years of scientific endeavor attempting to understand the properties of this enigmatic metal.American and Russian scientists had disagreed for 40 years on how to tame plutonium’s notorious instability, when, in 1998, I began working with Lidia Timofeeva, the preeminent Russian plutonium metallurgist. The end of the Cold War enabled us to talk, challenge each other’s views, and finally understand this element better. Our joint work demonstrated the validity of Russian research finding that a high-temperature phase of plutonium could be retained at room temperature, but not stabilized, by adding small amounts of gallium. (We published the results in a paper called “A Tale of Two Diagrams.”) US-Russian collaboration at more than a dozen plutonium science workshops continued for 15 years. 

Computing power

Computational methods for massively parallel computing became a third important topic of scientific collaboration. During the 1992 US lab directors’ visit to Sarov, I was surprised by VNIIEF’s computational capabilities. Soviet computers were known to be greatly inferior to US supercomputers, the most powerful of which resided at the Los Alamos and Lawrence Livermore laboratories. Yet their three-dimensional simulations of a representative ballistic impact problem were extraordinary. When I marveled at my counterparts’ computing abilities, one of them explained, “since we don’t have the computing power you have, we have to think harder”—and they did. More than one thousand specialists worked in VNIIEF’s Mathematical Department, including some of the most gifted Russian mathematicians and computer scientists. 

Because only low-performing, single-central processing unit (CPU) computers were available to Russia’s scientific institutes, in the 1970s VNIIEF began to physically link CPUs and create parallel software algorithms that efficiently used multiple CPUs to greatly accelerate simulations for problems such as hydrodynamics, heat conduction, and radiation transport. They confirmed the efficiency of their parallelization strategies on computers with up to 10 CPUs, the most they could link at the time. They also developed analytical models for predicting the scaling efficiency to arbitrarily large numbers of processors.

During this time, the American labs were just beginning to transition their nuclear simulation codes from powerful single-CPU computers to the massively parallel computers that were becoming commercially available, a transition the Russian side had accomplished years earlier but with fewer and less powerful CPUs. Our collaborations gave Americans access to proven parallelizing algorithms, and gave Russians the ability to evaluate different analytical models for predicting the scaling efficiency to large numbers of processors. This same technology would later prove critical to both US and Russian programs for maintaining their arsenals after nuclear tests were banned.

Allowing the nuclear weapons scientists to move out of the shadow of Cold-War secrecy through scientific collaborations made us realize how much we were alike. It helped build trust, which had a powerful impact on enhancing nuclear security because it allowed us to extend our collaboration into sensitive subject areas, like the safety and security of nuclear weapons and materials. For the nuclear weapons scientists, the progression from science to security was a natural evolution, since we had practiced both from the beginning of our nation’s nuclear programs. It also fulfilled our desire to apply our skills to enhance scientific progress.

MEDIA CONTACTS

Siegfried S. Hecker, Center for International Security and Cooperation: (650) 725-6468, shecker@stanford.edu

Clifton B. Parker, Center for International Security and Cooperation: (650) 725-6488, cbparker@stanford.edu