Meanwhile, the United States would likely have been in a far weaker position in 1945 without World War II. Wartime mobilization doubled America’s GDP, and when Germany and Japan surrendered, the U.S. possessed half the planet’s industrial capacity. The G.I. Bill, one of the largest investments in human capital in history, and the Interstate Highway System, the largest infrastructure investment in U.S. history, are a direct result of American participation in the war. The America we know today would be scarcely recognizable without them.
Perhaps most crucially, Hitler’s rise forced many of Europe’s top physicists, chemists, mathematicians, and other scientists to seek refuge in the United States. Among them were some of the most famous names in modern scientific history, including Albert Einstein, Niels Bohr, Enrico Fermi, Leo Szilard, and more. Fearing Hitler’s ambitions and armed with the knowledge that Germany had its own nuclear program underway, Einstein and Szilard persuaded Franklin D. Roosevelt in 1939 to launch what would become the Manhattan Project. Bohr, Fermi, Szilard, and dozens of other European scientists subsequently participated in it to develop the world’s first nuclear bombs.
What if that intellectual power had remained in Europe? What if Fermi had created the first artificial nuclear reactor in Mussolini's Italy instead of beneath the University of Chicago’s football stands? What if, during some moment of international tension, Einstein wrote to the leader of Germany and warned him about a nuclear-weapons program in the Soviet Union or the British Empire? What if atomic bombs had been first deployed not to end a war, but to begin one?
These questions should inspire two feelings. The first is humility. We can never know what a universe without Hitler would have looked like. But the implicit argument that his removal would improve history must also consider that his removal could make it worse. Indeed, recent experience should make us doubt our abilities to bend the course of human events towards our will. The Bush administration naively claimed that toppling Saddam Hussein in 2003 would produce a vibrant liberal democracy in the largely illiberal Middle East. Instead it brought about regional instability, ethnic cleansing, civil war, and ISIS.
The second is relief. We live in cynical times, which masks the fact that we live in extraordinary times. Atrocities still occur, but human rights are now a normative value throughout most of the world, even if their enforcement is imperfect. Conflicts are still fought, but the great powers have avoided another world war for seven decades. Racism and anti-Semitism still exist, but pre-war forms of colonialism and pogroms have largely disappeared. This is not the future for which Nazi Germany fought and fell. Removing Hitler from history would gamble with one irrefutable truth: He lost.
I could be wrong about all of this. If you have another perspective on the question or a different interpretation of history, I’d love to hear it. Email us at hello@theatlantic.com.