How do you solve a problem like nukes?

by Ashutosh Jogalekar

As the saying goes, if you believe only fascists guard borders, then you will ensure that only fascists will guard borders. The same principle applies to scientists working on nuclear weapons. If you believe that only Strangelovian warmongers work on nuclear weapons, you run the risk of ensuring that only such characters will do it.

We can therefore be thankful that there are sane scientists with diverse opinions about America’s nuclear weapons who work on these fiendish creations. And we can be doubly thankful that journalist and writer Sarah Scoles has taken the trouble to write about them in her book, “Countdown”. Scoles has an eye for the interesting, the droll and the ironic. She tours the sites where nuclear weapons have been developed and maintained – most notably America’s national labs – and spends ample time with a handful of scientists and engineers who work with them. She talks at length to these patriotic men and women and paints a revealing portrait of people who, apart from their work, are just…well, people. They have families and hobbies and take their kids to soccer and swim practice. They love to chat up their neighbors and drink wine with them. They love to argue and are well aware of both sides of the debate. They are smart and highly skilled at their trades. Most importantly, while they would like to see a world free of nuclear weapons, they know that until that happens, deterrence is our best bet to keep the peace. They have taken it upon themselves to shoulder that grim responsibility. We should be glad that America’s nuclear weapons are in such safe hands.

But deterrence only works when its reliable. That is where the crux of the problem, and the main narrative of Scoles’s book, lies. You can only deter an adversary if you and the adversary believe that the weapons you are using to deter them work and are foolproof. You can only ensure the workings of a weapon if you test it on a regular basis. And since 1992 after the Cold War ended, the United States has not done any full-scale tests of a nuclear weapon. Doing such tests would be a major destabilizing move against Russia and China, still our most important adversaries when it comes to nuclear weapons. But not doing tests risks reducing the reliability of our nuclear weapons and undermines the very idea of deterrence. Therein lies the dilemma.

The scientists featured in Scoles’s book work on myriad creative ways to defuse the dilemma. Tess Light and Josh Carmichael at Los Alamos National Laboratory have built an integrated system to detect nuclear tests. The system assesses seismic, optical and other signals, on the ground and in space, to provide an integrated picture that would make it possible to declare with high probability whether another country has tested a nuclear weapon.  John Martz and David Clark work on ensuring the quality and function of the plutonium pits which form the heart of the bombs. Other scientists, at Lawrence Livermore and Sandia National Labs in particular, work on preserving the integrity of the explosives that trigger the nuclear reaction; on the electronics that provide both function and safeguards in the weapons; on models of how radioactive material might disperse in a city after a terrorist attack; on waste management; and on the chemistry and physics of exotic materials that orchestrate the “physics package” that makes a nuclear weapon detonate. In many ways nuclear weapons are no different from a complicated machine with a lot of working parts, and you need both responsible personnel and a reliably supply chain system to ensure that these weapons work only when they are needed and never otherwise.

Making sure that they do, however, is far from trivial in the absence of actual testing. ‘Stockpile security’ refers to the combined set of inspections, tests and measures designed to maintain the security of the stockpile without physical testing. Computer simulation plays a huge role in this process; if you cannot test a weapon in reality, perhaps you can at least do it on a computer by simulating the complex radiation and hydrodynamics of a nuclear explosion. In addition, “subcritical” tests which measure the parameters of the non-nuclear components of nuclear weapons can be conducted underground. But anyone who has done computer simulations for a long time knows that the devil is in the details. Computers can be good at understanding complex systems like proteins, the climate and nuclear weapons, but are typically poor at predicting them. Especially when it comes to predicting how well our existing weapons which haven’t been tested for decades will do twenty, fifty or a hundred years from now, simulations can at best be only a partial guide.

The biggest uncertainty is in predicting the integrity of plutonium pits. Because plutonium is radioactive and emits short-range but energetic alpha particles, it can damage its own crystal structure and that of the materials around it after a while, making them unreliable. Even experts would find it hard to say with confidence that a plutonium weapon would work the exact same way in a hundred years as it does now. Because of these issues, for the first time since the Cold War the Biden administration has asked the national labs to restart the production of plutonium pits to replace aged pits, with a target of thirty pits per year by 2030. Nuclear activists have loudly protested this action. Nuclear proponents have said it’s critical for deterrence which works only when it’s true.

The scientists’ work featured in this book is both technically interesting and exciting. And it is necessary. But it does not make the fundamental problem of deterrence go away. Currently the United States and Russia have between them roughly 3000 warheads. If these are all fired it will lead to an unmitigated catastrophe, with hundreds of millions of instant deaths and billions subsequently because of nuclear winter and other environmental effects. Humanity will inhabit a wasteland that Cormac McCarthy might have been hard-pressed to imagine. A system with so many weapons and moving parts is subject to what the technologist Charles Perrow once called “normal accidents”, which are accidents that happen because of the intrinsic complexity of a system, both technical and human. The book documents several lapses of security and accidents riddling the labs that illustrate how the system is more fragile than we think. At one point, someone interpreted a requirement for shipping radioactive material as containing “an organic” kitty litter instead of “inorganic” kitty litter, causing the contents to leak. In another notorious case, careless employees in order to impress their boss kept a few plutonium ingots next to each other for taking a photo, not realizing that the system was edging so close to criticality that a few more ingots would have resulted in a fatal burst of radiation.

No matter how much we take care of our nuclear weapons, one can go off because of accident, or human error, or deliberate malice. A false signal from a computer malfunction – an event that has happened more than once during the Cold War – could lead a trigger-happy leader to order a retaliatory launch. Because of both the short amount of time available to make decisions and the inherent complexity of the system, escalation is very easy, and a “limited nuclear war” is more wishful thinking than reality. And even a limited war would cause unimaginable casualties. Deterrence might feel like a stable equilibrium point, but in fact it’s like a ball perched on the edge of a cliff.

Because of these inherent problems with deterrence, getting rid of the weapons is the only truly safe ultimate strategy. Unfortunately two factors have made this goal complicated. One is the rise of Russia and China, both of whose leaders are behaving like old-fashioned 20th century dictators trying to grab land and fight proxy wars. The second is political dysfunction in the United States. During the Cold War, whatever other policy differences the two parties had, they could agree on who America’s friends and enemies were. They could also agree that America needed to negotiate with both its friends and its enemies. From Eisenhower to Clinton, both Democratic and Republican presidents worked with Soviet leaders to reduce the tension and try to reduce the arsenals. It was two Republican presidents – Ronald Reagan and George H. W. Bush – who got rid of the most nuclear weapons. Unfortunately today, one party is weak and the other jingoistic. Patriotism has become a dirty word, especially among liberals, even though the scientists featured in Scoles’s book call themselves both liberal and patriotic.

The road ahead will be complicated in the face of a changing world with uncertain geopolitics, but a few directions seem clear. First of all, we need to be able to negotiate with Russia and China no matter how bad things get. Keeping backchannels open and agreeing on the common threat of nuclear war even if we disagree on everything else would be critical. Second, we need to make commonsense patriotism great again by realizing that there are some things that transcend party loyalty and political differences. Liberals and conservatives need to come together to work together on America’s defense in a non-partisan manner. Third, nuclear weapons need to occupy the same space of urgent public consciousness that is currently occupied by climate change, immigration and other topics which often generate more heat than light. Fourth, and invoking Niels Bohr’s principle of complementarity, we need to believe two seemingly opposite ideas: that we can work toward a world free of nuclear weapons, and that we also need to ensure until then that we have a strong deterrent, all the time also reducing our arsenals down to a few hundred at best.

Few individuals have done more to reduce the threat of nuclear war than the late physicist Sidney Drell. Drell once visited a weapons base near Seattle and met the able men and women who were dedicating their careers to the care and maintenance of nuclear torpedoes. Just like Scoles’s scientists and engineers, these men and women were superb craftsmen and took pride in maintaining what was an elegant weapon. Drell appreciated what they were doing, but he compared their craftsmanship as being in the same spirit as that of the craftsmen creating Stradivarius violins. What if we lived in a world, Drell wondered, where these men and women could spend all their time tending Stradivarius violins instead of nuclear torpedoes? We can wish the same for our nuclear scientists and must keep striving toward that world. But until that time comes, the plutonium pits need their attention.