This piece analyzes two distinct periods of significant globalization—one preceding World War I and the other starting in the late 20th century—highlighting the parallels in their rapid expansion and subsequent collapse. It explains how technological advancements facilitated increased interconnectedness in both eras, leading to booming trade and migration, and how many observers believed these trends were irreversible. The text emphasizes the economic disruptions and rising inequality that accompanied both periods of intense globalization, contributing to antiglobalist backlashes, the rise of authoritarian movements, and international conflicts. Finally, it suggests that addressing the negative consequences of globalization, particularly inequality, is crucial to avoiding a catastrophic outcome similar to the one that followed the first period of globalization's decline.