Mutually Assured Destruction: Game Theory in the Cold War
http://science.howstuffworks.com/game-theory5.htm
The article excerpt talks about how Game Theory played an important role in the great nuclear passive-aggression that was the Cold War. The United States was the first country to develop nuclear weaponry. Nuclear weapons were originally treated the same as more traditional components of the U.S. arsenal, to be used when necessary as an impediment to enemy forces. Since the U.S. was the only country with nuclear weapons at the time, a typical wartime situation could be represented as such-
Let the U.S. be engaged in military conflict with an enemy state. Let losses from traditional warfare be represented as the negative of casualties (scaled down). Then the payoff based on the U.S. decision to use nuclear weapons can be shown as-
| Enemy state | |
| United States
Use Weapon |
0, -1000 |
| Do not use weapon | -5, -5 |
Clearly, using nuclear weapons is a dominant strategy for the USA. The only use of nuclear weapons in humanity’s history occurred when this situation was applicable.
However with the passage of time, other nations- in particular the USSR caught up with the US in terms of nuclear technology. This transformed the way the US (and other nuclear powers) viewed atomic weapons. Since each nation promised to retaliate in kind if nuclear weapons were used averse to their interests, the perception of these weapons changed from arms that could be engaged in any conflict to deterrents that were never to be used lest it provoke retaliation. Thus the payoff grid changed to something like this-
| Nuclear Power 2
Use Weapon (U2) |
Do not use weapon (D2) |
|
| Nuclear Power 1
Use Weapon (U1) |
-1000, -1000 | —– |
| Do not use weapon(D1) | —– | 0, 0 |
There is no dominant strategy here as the result depends on the decision of the other participant. The safest choice to make for each nuclear power was not to use their weapons, since using them would provoke Mutually Assured Destruction (MAD). This situation characterised most of the Cold War. This had severe implications as pointed out in the article. For instance- “If one nation changed the balance of power (by building a missile-defense shield, for instance), would it lead to a strategic blunder that resulted in nuclear war?”. In terms of our model, if nation 1 built a missile shield, the cell U1-U2 of the above grid would change its weights to something along the lines of 0, -1000, similar to the value in the very first grid. No longer bound by the promise of mutual destruction, nation 1 could now use its weapons without nation 2 being able to do significant damage in return. This would make using its weapons the dominant strategy. Because of this, countries treated each other’s technological advancements with great distrust, as they could alter the parameters of the MAD situation and enable dominant strategies to exist. As a result “governments consulted game theorists to prevent such imbalances. When one nation built missile silos, the other nation targeted them. The Soviet Union and the U.S. then spread out and hid their launch sites around the globe, which required both nations to commit more missiles to a potential first strike in order to diminish the retaliatory abilities of the other.” Thus, each move in the Cold War was either an attempt to create a dominant strategy for oneself or to ensure the opposing side did not create one.