Diplomacy resembles chess. Each player must make his key moves in such a way as to anticipate the moves of his opponent. In the game of diplomacy, self-interest is the only sound basis on which to predict the reactions of the other nation. Thomas A. Bailey, The Art of Diplomacy (1968).
The card game discussed in Chapter 1 showed that there may be situations in which at least some countries behave in a way that harms the collective good. The fur seal story, told in Chapter 2 , showed something similar. For forty years, too many seals were killed and by the wrong methods. This chapter exposes the fundamental forces that can cause collective destruction.
In both the card game and the fur seal case, the outcomes depended on the nature of the underlying problem, as specified by the rules of the game. In the card game, these rules described the rewards for every player. They also determined whether the players could communicate with one another, whether the actions taken by the players were publicly observable, and whether the parties were able to appeal to a third party for enforcement. In the fur seal story, the underlying problem was determined by a similar set of rules—and more, including the three-mile territorial limit and the feasibility of re-flagging. Also important was the biology and behavior of the fur seal. Recall that the sea otter was eliminated from the Pribilofs soon after the islands were discovered. The fur seal proved more resilient to the hunt, though it may have become extinct eventually were it not for the treaty.
As suggested by these examples, some rules, such as the fur seal's biology, are determined by nature. Others, like the three-mile limit, are human inventions, determined in a kind of meta game of international relations.
For both the card game and the fur seal story, the outcomes also depended on the behavior of the parties—that is, on how they responded to the incentives structured by the rules of the game. Some players in the card game handed in their red cards and some did not, even though every player faced precisely the same incentives. Something similar emerged from the telling of the fur seal story. After other approaches failed, the United States unilaterally prohibited its own citizens from sealing at sea, essentially handing in its red card. Canada did not reciprocate.
The outcomes we observe—the number of red cards handed in, the stock and culling rate of seals, the depositions of acidic compounds, and so on—all these outcomes depend on the interplay between these two forces: the rules of the game and the way that the players respond to these rules. This interplay may lead to a “tragedy