In 2016, the United States was stunned by evidence of Russian meddling in the US presidential elections. But it shouldn't have been. Subversion—domestic interference to undermine or manipulate a rival—is as old as statecraft itself. The basic idea would have been familiar to Sun Tzu, Thucydides, Elizabeth I, or Bismarck.

It came as a surprise in 2016 because the sole superpower had fallen asleep at the wheel. But what's really new? Have we entered a new age of vulnerability? To answer these questions, and to protect ourselves against future subversion, we need a clear-eyed understanding of what it is and how it works.

In A Measure Short of War, Jill Kastner and William C. Wohlforth provide just that, taking the listener on a compelling ride through the history of subversion, exploring two thousand years of mischief and manipulation to illustrate subversion's allure, its operational possibilities, and the means for fighting back against it. With vivid examples from the ancient world, the great-power rivalries of the nineteenth century, epic Cold War struggles, and more, A Measure Short of War shows how prior technological revolutions opened up new avenues for subversion, and how some democracies have been fatally weakened by foreign subverters while others have artfully defended themselves—and their democratic principles.