The Balance of Terror — A Peace Secured by Annihilation

When the Second World War ended, the only nation that possessed the atomic bomb was the United States. Yet that monopoly did not last long. As we saw last time, it had already become known to the world that a nuclear weapon held the power to take an entire city with a single blast. If only the other side were to hold that power — this fear drove the two postwar superpowers into a competition with no end in sight. Before long, both nations came to hold enough nuclear weapons to destroy each other any number of times, and entered a strange balance in which they kept the peace by securing each other’s ruin. This is the story of the nuclear weapons of the era called the Cold War.

The End of the Monopoly — The Soviet Union Catches Up

How long would the United States’ nuclear monopoly last? Among the postwar leaders, some are said to have believed that advantage would hold for a long time. But in 1949, the Soviet Union is said to have succeeded in its first atomic bomb test, and that outlook collapsed. The era in which the United States was the world’s only nuclear power ended in just a few years.

The Soviet Union’s first atomic bomb is also said to have drawn on American designs. There is a view that intelligence activity from wartime into the postwar years lay behind this, but in any case, the fact that the two great powers both came to hold nuclear weapons changed the dynamics of the world from their foundations. If one side attacked, the other could retaliate with the same power. This simple yet weighty structure would bind international politics from here on for decades.

By this time, the world was already splitting into two camps, the United States and the Soviet Union. Without exchanging direct fire, they continued in confrontation and tension with each other — a state later called the Cold War. It was not a hot war, yet it could by no means be called peace either: a taut age. At the innermost depth of that tension, the existence of nuclear weapons was always present. The wish to stand even a little above the other pushed both nations out into an endless race of development.

The Sun’s Fire — The Hydrogen Bomb Appears

The competition, which not even the atomic bomb could contain, gave birth to a weapon of yet another order. The hydrogen bomb. Whereas the atomic bomb draws power by splitting atomic nuclei, the hydrogen bomb makes use of a reaction that fuses light atomic nuclei. This is the same kind of reaction by which the sun produces energy, and its power far surpassed that of the atomic bomb.

In 1952, the United States is said to have conducted its first hydrogen bomb test at an atoll in the Pacific, and its explosive force is said to have reached a scale described as hundreds of times that of the Hiroshima-type atomic bomb. Among those who witnessed the test, it is passed down, there were some who felt they had seen something that could no longer be captured by the word ‘weapon.’ The following year, 1953, the Soviet Union too is said to have succeeded in a hydrogen bomb test, and the competition advanced to a new stage.

And in 1961, the test the Soviet Union conducted on an island in the Arctic, called Tsar Bomba, is known as one of the largest nuclear explosions in history. An age had arrived in which a weapon whose single blast might exceed a thousand times that of the atomic bomb actually existed. Its flash could be seen from hundreds of kilometers away, and its shock wave is said to have circled the earth several times. Ironically, a weapon this enormous had almost no use in actual combat; it is said rather to have carried strongly the color of a symbol — a way of showing off one’s own power to the world. The competition in sheer power had, at some point, gone beyond the frame of practical use and advanced to a stage of flaunting terror itself at one another.

Mutual Assured Destruction — A Peace Secured by Annihilation

As both nations piled up an immense quantity of nuclear weapons, the hydrogen bomb among them, one strange logic took shape. Mutual assured destruction, a way of thinking called MAD after the initials in English. This was the reasoning that even if one side launched a first strike with nuclear weapons, the side that was attacked would surely retaliate with the nuclear weapons that survived, and in the end both would be annihilated — and that for this very reason, neither could bring itself to take that first blow.

In other words, it is the paradox that peace is kept because each can destroy the other. The certainty of retaliation was thought to be what prevented war, and for that purpose both nations dispersed their nuclear forces across land, beneath the sea, and into the air, so that they could strike back even if attacked, building up a posture able to fire back at any time. Missiles set in underground silos, submarines moving quietly along the seafloor, bombers waiting in the sky — even if any one of them were lost in a surprise attack, the rest would surely retaliate. Such a mechanism was what supported the certainty of retaliation.

To furnish more destructive power for the sake of safety. This idea bred a vicious circle without limit. If the other increased, this side increased too. If a new weapon appeared, one developed something to surpass it. Preparations made for defense, instead, stirred up the other’s unease and called forth still more arms buildup — later this structure came to be spoken of as the security dilemma as well. The more one sought safety, the more the world as a whole became, on the contrary, precarious. The balance of terror was a peace that held such precariousness within itself.

The structure in which terror supports peace seemed stable, yet it was by no means something one could rest easy with. The logic holds only as long as both sides are calm, the information is accurate, and the machines do not err. A mistake in judgment, a confusion in communication, the merest chance — let one of these overlap, and the balance could easily collapse. Indeed, in the midst of the Cold War, a moment came when humanity was driven to that very brink. The stockpiled weapons were, one autumn, brought to the very edge of use. Next time, we trace the tense thirteen days when the world is said to have come closest to its own extinction.