Without a doubt, oil was the most important commodity in the twentieth century. Oil was literally the fuel of the previous round of globalization at the end of the nineteenth century and lasting until World War I. Its importance continued to increase as the main fuel for war machinery, and then to fuel the global growth between the two world wars and following World War II. The roots of increased demand and dependence on oil, which continue to shape current and future demand, were set in the mid-to-late nineteenth century.

Trends in oil demand are highly correlated with rates of economic growth, modes of transportation and production, and wealth accumulation. It is on the supply side that strategic behavior becomes more interesting. Following very high prices in the U.S. in 1860, during the Civil War, a classical case of “tragedy of the commons” emerged. The law of capture in the United States, which was then the fastest growing region for demand and economic growth, encouraged excessively fast oil extraction and reduced prices precipitously.

Excessive extraction and lower prices are, of course, the economic outcomes theoretically predicted in a competitive environment. Rockefeller's Standard Oil restored higher prices by monopolizing production in the United States. Antitrust law eventually broke Standard Oil's monopoly, but the idea of strategic control of supply never died. Starting in the 1920s, an international oligopoly of large oil companies emerged.