The most spectacular event of the past half century is one that did not occur. We have enjoyed sixty years without nuclear weapons exploded in anger.
What a stunning achievement—or, if not achievement, what stunning good fortune. In 1960 the British novelist C. P. Snow said on the front page of the New York Times that unless the nuclear powers drastically reduced their nuclear armaments thermonuclear warfare within the decade was a “mathematical certainty.” Nobody appeared to think Snow’s statement extravagant.
We now have that mathematical certainty compounded more than four times, and no nuclear war.
– Thomas Schelling, 2005 Nobel Prize in Economics Lecture
When Robert McNamara was named the Secretary of Defense in 1961, he brought to the Pentagon a group of aides who came to be known as the Whiz Kids. They were young, book-smart men eager to apply the latest in systems analysis, game theory, and operations research to military strategy.
It did not take them long to alienate senior officers. Once to settle a particularly heated argument about nuclear plans, a 29-year-old Whiz Kid declared: “General, I have fought just as many nuclear wars as you have.”
The flip remark understates a fact that deserves great wonder: The world has now gone for seven decades while avoiding nuclear destruction. The thermonuclear war that was once regarded with the greatest of fears and as a mathematical certainty has not come to pass.
In addition, it’s also a startling display of the role that a group of civilians played in defining U.S. nuclear strategy. After a first draft by the military, American strategic objectives were subject to continuous refinements. Many of these refinements came from civilian theorists, most of whom came from the RAND Corporation, and few of whom had seen war. One of the earliest nuclear intellectuals from RAND started out as a naval strategist; when he produced his most important work on naval strategy, he had never seen the ocean, let alone set foot on a ship. In seminar rooms, these strategists pondered the novel challenges of the nuclear world and worked out ideas by discussing not the efficient application of force but rather the exploitation of potential force.
This essay is a short introduction to how nuclear weapons are created and deployed, and the ideas that strategists, policymakers, and the military implemented to reduce the risk of nuclear war.
(Published in prettier formatting on Medium.)
What Are Nuclear Weapons?
Thirty years after the detonation on Hiroshima, the world had produced enough nuclear weapons to create the equivalent of about 3 tons of TNT for every man, woman, and child on earth. Here’s context to put that figure into some sort of perspective.
Nuclear Explosions
What happens in a nuclear explosion? First, a huge blast drives air away, producing high winds and changes in air pressure that crush objects. Then come radiation: direct radiation will cause fatal illness in a matter of a few weeks, while thermal radiation will cause first-degree burns a few miles away. Fires immediately follow; a strong blast can generate a firestorm, which destroys everything in a concentrated area, or a conflagration, which is not so strong but spreads along a front. Then there’s fallout: particles are scooped up from the ground, get irradiated by the explosion, and spread depending on wind conditions. Finally, at a sufficiently high altitude, a blast might produce electrons that interact with the earth’s magnetic field, setting off an electromagnetic pulse that can destroy electronics and metal objects.
The world has set off over 2400 nuclear explosions, nearly all of them by America or the Soviet Union, most of them underground. Americans have tested most of their weapons in the southwestern states of Nevada or New Mexico, or on islands in the Pacific. The Soviet Union has conducted mostly in Kazakhstan or archipelagos in the Arctic Ocean.
Nuclear detonations have been set off underground, underwater, and in the atmosphere. They’ve had usually minor and sometimes permanent effects on the earth. As a dramatic example, America’s first hydrogen bomb, named “Ivy Mike,” completely obliterated the small Pacific island on which it was tested.
The effects of nuclear explosions have always provoked anxiety. Before the first nuclear test in New Mexico, Enrico Fermi rounded up his fellow scientists to place a grim bet. Some of them speculated that an atomic bomb would ignite the atmosphere, and Fermi offered wagers on whether the Trinity test might destroy the atmosphere of the planet, or merely that of New Mexico state. More recently, Carl Sagan wrote that instead of igniting the atmosphere, nuclear weapons may cool the world enough to produce a nuclear winter.
The effects of nuclear tests have not always been well controlled. Shortly after the Ivy Mike test, America detonated the most powerful thermonuclear bomb it would ever construct. “Castle Bravo” was expected to yield a blast of five or six megatons, but instead produced a blast of 15 megatons. The blast carried fallout to inhabitants on the Marshall Islands, some of whom ate the radioactive powder they believed to be snow. Hundreds were overexposed to radiation, and a nearby Japanese fishing ship crew suffered from radiation poisoning. Fallout from that blast eventually spread 7,000 miles, including to India, the United States, and Europe.
The Mechanics of Atomic and Hydrogen Bombs
There are two types of nuclear bombs. The atomic bomb creates temperatures equal to those on the surface of the sun; and the much more powerful hydrogen bomb bring the equivalent of a small piece of the sun to earth.
The basic nuclear weapon is the atomic bomb, otherwise known as the fission bomb. Atomic bombs typically have yields measured in the thousands of tons of TNT, or kilotons. Their explosive force is generated from a fission process; fission occurs when a neutron enters the nucleus of an atom of a nuclear material, which is either enriched uranium or enriched plutonium. A large amount of energy is released in the process, which causes the nucleus to release a few more neutrons. In the presence of a critical mass, these neutrons go on to create a chain reaction. There are two types of bomb designs for initiating fission. The first is the gun assembly technique, which brings together two subcritical masses to form a critical mass; the second is the implosion technique, which compresses a single subcritical mass into a critical density.
On August 6th, 1945, the U.S. Air Force dropped the atomic bomb known as “Little Boy” on Hiroshima. Little Boy was a gun-type bomb with a core of 60 kilograms of uranium-235. About 700 grams of it fissioned (just over 10%), generating a blast of 12.5 kilotons; about 60,000 to 80,000 people were killed by the blast, while up to twice that number were killed by burns and radiation. Three days later, the U.S. dropped an atomic bomb on Nagasaki. The Nagasaki bomb, known as “Fat Man,” was an implosion-style bomb carrying 8 kilograms of plutonium-239. Once again about 10% of the material fissioned, producing a yield of about 22 kilotons and instantly killing about 40,000 people. The complete detonation of its plutonium would have caused an explosion 10 times its size.
The more sophisticated and far more destructive kind of nuclear weapon is hydrogen bomb, otherwise known as the thermonuclear bomb, the fusion bomb, or the H-bomb. In hydrogen bombs, heavier isotopes of hydrogen are fused together to form helium. That reaction creates a great deal of energy, far more than the chain reaction possible in fission bombs. Hydrogen bombs are far more difficult to construct than the atomic bomb; nine countries possess nuclear weapons, but only five have definitely developed hydrogen bombs. A successful detonation requires the explosion of a fission bomb (the “primary”) to ignite a fusion (the “secondary”). The difficulty presented by the hydrogen bomb is the risk that the atomic bomb might explode prematurely and blow up the whole bomb, an event referred to as a “fizzle.”
Hydrogen bombs are hundreds or thousands of times more powerful than atomic bombs. The first hydrogen device, which couldn’t be used as a weapon, was detonated by the United States in November of 1952. A true hydrogen weapon was not detonated by America until March, 1954. The bomb, Castle Bravo, was the most powerful nuclear explosion America would ever generate; at 15 megatons, it was over 700 times more powerful than the blast at Nagasaki. The Soviet Union would detonate its first hydrogen bomb in November, 1955. In 1961, it would go on to detonate the largest nuclear weapon ever: The Tsar Bomba had a yield of over 50 megatons, or over 2500 Nagasakis.
The value of a weapon of these sizes is not immediately obvious. A 1-megaton bomb would kill most people within hundreds of miles, while the largest of cities would be destroyed by a bomb of 10 megatons.
How Are Nuclear Weapons Delivered?
There are two types of nuclear deployments. Strategic weapons are launched against homelands, while tactical weapons are used on battlefields.
Strategic nuclear weapons are typically delivered in one of three ways. First, they may be launched from bombers; these can either take the form of free-fall gravity bombs or as air-launched cruise missiles (ALCMs). Second, they’re deployed on intercontinental ballistic missiles (ICBMs), which are launched from underground silos and are capable of reaching any target on earth. Finally, submarine-launched ballistic missiles (SLBMs) are deployed by submarines, which can lie at sea for months and surface only to launch. The majority of warheads are deployed on ballistic missiles, while a few hundred are located at bomber bases.
There has been a greater variety of tactical nuclear weapons, though they’re no longer deployed. They were once a regular part of arsenals, including as torpedoes, mines, artillery, and rocket launchers. A young Colin Powell was an officer stationed in West Germany in 1958 when he was tasked with guarding against a Soviet invasion; if the enemy came over, he was to launch 280 mm atomic cannons, which fired artillery shells with yields of 15 kilotons (or about the explosive force of Hiroshima). These tactical weapons have never actually been put to use.
Stockpiles
The global nuclear stockpile peaked at 70,000 weapons in 1986. Most have been owned either by the Americans or the Soviets.
Both countries have vastly reduced their arsenal. In the last 25 years, America has reduced its stockpile from about 23,000 weapons to around approximately 7000 today. Meanwhile, Russia has brought down its stockpile to around 8000 weapons, from a peak of 30,000 inherited from the Soviet Union.
There are seven other countries with confirmed nuclear weapons: France, China, the U.K., Pakistan, India, and North Korea. Israel is rumored but not officially confirmed to have nuclear weapons. Of all nine countries, five are confirmed to have hydrogen bombs: the U.S., Russia, France, China, and the U.K. India has claimed to have detonated a hydrogen bomb, but scientists debate whether it was a true two-stage thermonuclear device.
The vast majority of nuclear weapons are and have been operated by the U.S. and the Soviet Union; the stockpiles of other countries are miniscule in comparison. Currently France has the next largest stockpile, at around 300 weapons, while North Korea has fewer than 10. Motivations for acquiring the bomb have varied for every country. China, for example, sought not to depend too heavily on protection from the Soviet Union, just as Britain decided that it wanted warheads not controlled by America. Meanwhile, though France was motivated by a similar concern not to depend too much on the United States, it has also developed nuclear weapons because it craved status. Charles de Gaulle believed that that the bomb would “place France where she belonged, among the Great Powers.”
American Nuclear Strategy
As America demobilized after the Second World War, Eisenhower believed that nuclear weapons were a cheap substitute to maintaining a large army to deter Soviet aggression. With his Secretary of State John Foster Dulles, he defined a policy called “New Look” that relied on nuclear forces, as opposed to conventional forces, to deter aggression. The United States would be “willing and able to respond vigorously at places and with means of its own choosing.”
What did that mean in practice? At the discretion of the president, the entirety of the American nuclear stockpile would be delivered to enemy targets, both military and civilian. It was a first-strike policy: The enemy faced vast destruction if the United States determined that it crossed a line. Eisenhower and his staff considered it the ultimate deterrence.
It also attracted immediate skepticism from strategists. Critics of the policy considered it reckless and crude. First, it seemed practically an invitation for the Soviets to strike America; before a major action, Soviet forces should eliminate the American means to respond. Second, Eisenhower drew no bright line for incurring nuclear attack. Was America ready to initiate nuclear exchange, and guarantee the deaths of millions, in order to prevent a small country from turning Communist? What about Soviet meddling in the internal affairs of an allied country? In other words, this commitment to initiate exchange was insufficiently credible.
Strategists who made it their living to think about nuclear exchange attempted to make improvements. Many of the them were analysts at the RAND Corporation, a research institute set up by the Air Force to improve engineering and ponder novel scenarios for the modern world. These analysts tried to create options between official U.S. displeasure and full-scale thermonuclear exchange.
The rest of this essay is about certain ideas they developed to reduce the likelihood of mutual destruction. It gives a broad overview of the evolution of American strategic thinking, which started from massive deterrence, then moved through to reject elaborate methods of defense, and ended up on relying on once again on a robust system of deterrence.
Counterforce
William Kaufmann was a RAND analyst and political science professor who tried to create opportunities to wage limited war given weapons of unlimited power. He developed and was the proponent of a strategy that came to be known as “counterforce.”
There are two types of targets: military, which includes airbases, command stations, barracks, etc.; and civilian, which means cities and industrial sites. Early nuclear plans made no distinction between them. When authorized by the president, the stockpile would be launched against every target deemed to be valuable.
Kaufmann developed a different strategy: In case of conflict, not every warhead would be launched, and those that were launched would strike only military targets. The goal was to wipe out the enemy’s military capabilities while warheads held in reserve would threaten enemy cities. In the ideal world, after suffering a (reduced) retaliatory strike, the United States would have eliminated Soviet military capabilities and would be able to use Soviet cities as hostages to bargain for surrender.
What were the virtues of counterforce, as opposed to the cities-also countervalue, strategy?
First, civilians would avoid the brunt of the force. Vast numbers of innocents in cities would be largely spared. In a full-scale nuclear exchange, defense scenarios anticipated hundreds of millions of Soviet and American deaths, no matter who launched first. A counterforce strike also gives an incentive to the retaliating side to also target only military sites. A successful counterforce attack was projected to save over 100 million lives. Moreover, from a strategic standpoint, it created a chance for nuclear war to be limited. Counterforce offered the enemy an opportunity to recognize defeat early and so surrender with its civilian force intact.
The Pentagon warmed to counterforce. By 1962, Secretary McNamara publicly declared counterforce to be official U.S. policy, and encouraged the Soviets to adopt it as well.
It also had its skeptics, who argued that there were no guarantees that it might work as planned. When the enemy detected ICBMs, SLBMs, and strategic bombers racing towards its territory, it had no way to determine that it was subject to a “mere” counterforce strike. It was not clear that counterforce might really stave off escalation, and perhaps the simplicity of massive deterrence was still the best strategy after all.
Curtis LeMay, director of the Strategic Air Command (SAC), thought it meant going soft on the enemy; Thomas Schelling, who worked at RAND and consulted for the Pentagon, never fully embraced it; and even McNamara ended up skeptical of its usefulness. As a result, American nuclear strategy see-sawed between counterforce and massive deterrence; it would be integrated into nuclear plans, and then quickly stripped away, only to be re-introduced years later.
Conventional War
In addition to counterforce, Kaufmann also advocated for another way to keep war limited: Building up conventional military forces.
This was precisely the strategy rejected by Eisenhower. The Soviets were far superior in troops and tanks, enough to overrun Europe. Instead of trying to match their forces, Eisenhower wanted to rely on the massively-destructive and easily-deployable nuclear bomb to stave off attack or deter aggression in the first place.
But massive deterrence was risky. The enemy will try out many gray areas to test which actions were permissible; in each instance the American president has to decide whether it permits the action and lose face or launch the warheads, which risks national suicide while guaranteeing the deaths of millions.
Kaufmann thought that it was reckless to use nuclear weapons at all, save only in the gravest of circumstances. He observed that America’s most successful foreign actions were carried out without the use of nuclear weapons (as was the case with the Berlin Airlift and the intervention in Korea), and continued to believe that their use could be spared.
But it would require that the United States invest in different means for response. He suggested building up conventional forces, which meant included significant ground forces to beat back a Soviet invasion of Europe and smaller scale teams that can be rapidly deployed to “hot spots.”
In the logic of deterrence, an investment in conventional warfare is a signal that nuclear arms were too dangerous to be used. Building up conventional forces was advocated not only by Kaufmann but also important figures like Bernard Brodie and Herman Kahn, two of the earliest nuclear strategists. The growth of conventional forces in the Kennedy Administration was an acknowledgment to the Soviets that they could meet conflict without compelling the use of nuclear arms.
Schelling, in his Nobel Prize lecture, considered conventional forces to be a form of arms control, one as if both sides signed a treaty not to engage in nuclear change: “The investment in restraints on the use of nuclear weapons was real as well as symbolic.” With more options available, going nuclear was moved even further back to be the path of last resort.
SIOP: Single Integrated Operational Plan
Until the end of the Eisenhower Administration, nuclear target planning was delegated to senior military commanders. No single group or person oversaw the selection of targets nor organized the deployment of the nuclear force.
Take a second to imagine what that meant. The president had only the binary decision to strike or not strike. If he decided to strike, it’s up to the different services, each with their own stockpile, to deploy the weapons. The Air Force, the Navy, and the Army made their own war plans. Multiple, redundant warheads would be delivered to a target if it was selected by more than one branch. Due to a lack of coordination, an attacking force might be wiped out by the detonation caused by another American strike. Everyone launched at their own pace; the Navy was found to have been planning strikes fifteen days after the start of war.
This was the state of American nuclear plans for over a decade. The Joint Chiefs of Staff were resistant to the idea of a single branch, which would most likely end up being the Air Force, to control all warheads. The Navy was loath to give up its prized nuclear-armed Polaris submarines, and regarded all moves to centralize to be a plot by the Air Force to monopolize nuclear weapons.
It was only towards the end of the Eisenhower Administration that military objections were overruled. In 1960, Eisenhower authorized the creation of the Single Integrated Operational Plan (pronounced SEYE-OP) to coordinate a contingent plan of nuclear strikes. Only then did the United States integrate target selection into a national plan led by a single organization: the SAC.
SIOP went through different iterations. Some of them integrated the doctrine of counterforce, giving the president different options for launching strikes.
But still it didn’t eliminate concerns about overkill. SAC made extremely pessimistic assumptions about the probability of a successful strike. They planned to lay down four thermonuclear warheads with the power of 7.8 megatons for a Russian city the size of Hiroshima; the successful detonation of all of them would generate an explosive force 600 times more powerful than the 12.5 kiloton bomb that wiped out the Japanese city. It also did not consider the impact of fallout damage, because fallout generates little military value. These assumptions gave SAC the chance to constantly demand more bombs and bombers.
Still, most iterations of SIOP still emphasized the launch of nearly the entire stockpile. Plan 1-A would involve launching over 3000 nuclear weapons, projected to kill nearly 300 million people mostly in Russia and China. SIOP also targeted countries like Albania, for which the presence of a single large air-defense radar was enough to justify a strike by a megaton bomb; no consideration was given to the political fact that the country had been drifting away from the Soviet bloc.
SIOP was refined by different administrations and by different secretaries of defense, but it always suffered two flaws: massive overkill and relative inflexibility in the severity of response. Reading SIOP made presidents and generals feel “appalled” and “stunned”; it would be referred to by Henry Kissinger as a “horror strategy.”