World War I was the war that made the 20th century. It introduced humanity to the horrific potential for mass slaughter in the industrial age. It broke an international system that had prevailed for nearly 100 years, since Napoleon’s defeat. It turbocharged the toxic ideologies — fascism and communism — and the geopolitical tensions that made the 20th century an age of conflict.
Not coincidentally, the conflict also powerfully shaped our understanding of how the world works.
The systematic study of international relations, in universities and think tanks, was a response to the war of 1914-1918. Many ideas that shape current debates on foreign policy grew out of interpretations of how that war started and why it failed to produce a lasting peace. Even today, when analysts warn of an unwanted war with China, or bemoan America’s alleged lack of magnanimity following its victory in the Cold War, they are invoking perceived lessons of World War I.
Alas, some of the most commonly held ideas about the war are wrong — and they deeply skew our understanding of the modern world. For the U.S. to thrive in the great rivalries shaping this century, it must better understand the conflict that ushered in the last.
