It only sounds simple thanks to the professor. But the so-called correlated equilibrium - a theory where both parties can’t follow a dominant strategy and have only one chance of ‘winning’: an outside influence - is only one of his main contributions. And just a small part of the Nobel committee’s decision to award him its highest honor.
What can we learn from the Cold War?
"War is the one constant of mankind," he explains. It’s also a very significant constant in the life of an observant Jew. Sitting in his living room with his second wife Batya, he’s able to ponder his home-baked cheesecake with the same intensity as he philosophizes about his studies. But the old German recipe soon makes Aumann remembers his early childhood. Their upbringing in Nazi-Germany and the memories, as Aumann says, are still vivid in his mind. "In the store windows in Frankfurt, there was a sign with a light brown background and black lettering. It was in German, but was made to imitate Hebrew lettering. And it said: "Juden sind hier unerwünscht". Which means: Jews are unwanted in this store." There’s a moment of intimate silence while Aumann seems to travel through time, imitating the sound of the train that brought him away from his hometown Frankfurt. He becomes the eight-year-old boy he was in those days, his voice shaky, his eyes wet.
More or less ready to start over in the United States, "Johnny", as Aumann is known to his closest friends, saw the pressure of the Cold War. The nuclear threat not only had a significant impact on him personally, but also the development of game theory.
When the likelihood of nuclear war nears tipping point, it leads to Mutual Assured Destruction - where neither side has any incentive to either attack or disarm. The fear of being attacked by weapons of mass destruction prevents both sides from using them themselves. A kind of nuclear stalemate.
Why should we take revenge?
"There are all kinds of human traits that come out of repeated games," Aumann explains, referring to an ongoing conflict. "For example, revenge. Revenge doesn’t seem to make any sense. Why take revenge? You have already suffered some kind of loss, why does it help you to take revenge on the person that inflicted this loss?"
But Aumann argues that without revenge, there’s no deterrent. "So the revenge has to be part of the culture to enforce the cooperative behavior that takes place when people help each other, because they fear revenge. But that means that when they do harm each other, then the revenge has to be put into operation."
The crux of his theory leads to heated criticism when Aumann declares: "We need to be prepared for war; we must be willing to fight in order not to fight!"