The University of Michigan professor Robert Axelrod, foreseeing a lasting breakthrough in relations between the Russians and the Americans, wrote, “Once the US and the USSR know that they will be dealing with each other indefinitely, the necessary preconditions for cooperation will exist The foundation of cooperation is not really trust, but the durability of the relationship.”1
It is clear that if the Prisoner’s Dilemma is a one-time event, the rational strategy is mutual defection with a resulting low utility payoff. The question is different when one is likely to encounter the same opponent multiple times, and each player can consider what effect of his defection will have on the next encounter. Repeated, or iterated play of the Prisoner’s Dilemma may lead some to consider the idea of cooperation, but the temptation of defection and its higher payoff is always luring players to seek more.
The arms race was a prisoner’s dilemma that embodied the variation of the game that is exactly what Axelrod envisioned in noting the importance of engaging with the same opponent over time to reach the understanding that cooperation yields the best net outcome. The United States and U.S.S.R. knew that they would be dealing with each other for the long run—in effect repeating the game over and over again. In the area of arms control this ongoing engagement provided the possibility of knowing whether or not the other side was going ahead with development. This, in turn, permitted an agreement to slow development or halt testing, for example, if, and only if, the other side did the same. As well, it brought the gradual discovery over time that cooperation could result in spite of each individual country’s self-interest.
Examples of cooperation emerging in situations that involved choices between cooperation and defection have been noted in a wide range of areas from armed combat to animal behavior. One now famous example is a story from the trenches of World War I, brought to public attention in July 2001 with the death of Bertie Felstead at 106. The New York Times noted Felstead’s passing as the death of the last known survivor of the British battalion that on Christmas, 1915, near a small village west of Lille in France heard “All Through the Night” being sung one hundred yards away in the German trenches. Felstead’s unit was soon singing “Good King Wenceslas.” On Christmas Day shouts of “Hello Tommy, Hello Fritz,” were