Death's End

But an individual’s reaction could not be predicted.

The success of dark forest deterrence was founded on the unpredictability of Luo Ji as an individual. If deterrence failed, his actions would be guided by his own personality and psychology. Even if he acted rationally, his own interests might not match humanity’s interests perfectly. At the beginning of the Deterrence Era, both worlds carefully analyzed Luo Ji’s personality and built up detailed mathematical models. Human and Trisolaran deterrence game theorists reached remarkably similar conclusions: Depending on his mental state at the moment deterrence failed, Luo Ji’s degree of deterrence hovered between 91.9 percent and 98.4 percent. Trisolaris would not gamble with such odds.

Of course, such careful analysis wasn’t possible immediately after the creation of dark forest deterrence. But humanity quickly reached this conclusion intuitively, and the UN and the Solar System Fleet handed the authority to activate the deterrence system back to Luo Ji like a hot potato. The entire process from Luo Ji turning over the authority to getting it back took a total of eighteen hours. Yet that would have been long enough for droplets to destroy the ring of nuclear bombs surrounding the Sun and deprive humanity of the ability to broadcast their locations. The Trisolarans’ failure to do so was widely considered their greatest strategic blunder during the war, and humanity, covered in cold sweat, let out a held breath.

Since then, the power to activate the dark forest deterrence system had always been vested in Luo Ji. His hand first held the detonation switch for the circumsolar ring of nuclear bombs, and then the switch for the gravitational wave broadcast.

Dark forest deterrence hung over two worlds like the Sword of Damocles, and Luo Ji was the single hair from a horse’s tail that held up the sword. Thus, he came to be called the Swordholder.

The Wallfacer Project did not fade into history after all. Humanity could not escape the Wallfacers’ ghost.

Although the Wallfacer Project was an unprecedented anomaly in the history of humankind, both dark forest deterrence and the Swordholder had precursors. The mutual assured destruction practiced by NATO and the Warsaw Pact during the Cold War was an example of ultimate deterrence. In 1974, The Soviet Union initiated the Perimeter System (Russian Система «Периметр»), or “Dead Hand.” This was intended to guarantee that the Soviet Union possessed a viable second-strike capability in the event that an American-led first strike eliminated the Soviet government and high-level military command centers. The system relied on a monitoring system that gathered evidence of nuclear explosions within the Soviet Union; all the data was transmitted to a central computer that interpreted the data and decided whether to launch the Soviet Union’s nuclear arsenal.

The heart of the system was a secret control chamber hidden deep underground. If the system determined that a counterstrike must be launched, an operator on duty would initiate it.

In 2009, an officer who had been on duty in the room decades earlier told a reporter that at the time, he was a twenty-five-year-old junior lieutenant, freshly graduated from Frunze Military Academy. If the system determined that a strike was necessary, he was the last check before the complete destruction of the world. At that moment, all of the Soviet Union and Eastern Europe would likely be a sea of flames, and all of his loved ones above ground almost certainly dead. If he pushed the button, North America would also turn into hell on Earth in half an hour, and the following nuclear winter would doom all of humanity. He would hold the fate of human civilization in his hand.

Later, he was asked this question many times: If that moment had really arrived, would you have pushed the button?

The first Swordholder in history answered: I don’t know.

Humanity hoped that dark forest deterrence would have a happy ending, like the mutually assured destruction of the twentieth century.

Time passed in this strange balance. Deterrence had been in effect for sixty years, and Luo Ji, who was now over a hundred, still held the switch to initiate the broadcast. His image among the populace had also gradually changed.

Hawks who wished to take the hard line against Trisolaris did not like him. Near the beginning of the Deterrence Era, they advocated imposing more severe conditions on the Trisolarans, with the goal of completely disarming Trisolaris. Some of their proposals were absurd. For instance, one idea was the “naked resettlement” program, which would have demanded that all Trisolarans dehydrate and allow themselves to be transported by cargo ships to the Oort Cloud, where they would be picked up by human spaceships and brought to the Solar System to be stored in dehydratories on Mars or the moon. Thereafter, if the Trisolarans satisfied certain conditions, they would be rehydrated in small batches.