When it comes to foreign policy, the United States is notoriously averse to long-term thinking. Particularly since the end of the Cold War, our strategic culture has tended to cycle through fads, in which the terms of reference change even as the underlying policies remain continuous.

Partly as a corrective to this tendency, every four years, the Office of the Director of National Intelligence releases an unclassified report forecasting the future’s most significant geopolitical developments. The most recent of these, “Global Trends 2040: A More Contested World,” was published in April. If taken seriously, it offers a valuable guide to planning for the long haul.