You’re probably not making the same mistake about history that I made when I was younger. Back in the 1980s and early 1990s, as a kid in the US, I thought things always got better over time. History, I was taught, was pretty much a synonym for progress. I believed that was how history worked, for a while. As I got older, I learned that wasn’t the case. But I’m guessing that for you, growing up in the early twenty-first century, history doesn’t look like a straight line of progress. You have seen for yourself that as some things improve, others get worse.¹ As an American teenager growing up in an era of unprecedented economic expansion, however, I had not learned this lesson.

My grandparents knew, though. They grew up in, and fought in, and lost family in the world wars and atrocities that plagued the world between 1914 and 1945. This unit is all about those experiences.

Thirty years of war?

This unit begins with the First World War (1914–1918). This was a conflict caused by unrestrained nationalism, or maybe aggressive imperialism, or industrial militarism, or just a series of bad mistakes, depending on which historian you ask. Whatever the cause, it resulted in enormous death and suffering, including at least one genocide. The end of that war was followed by two decades of uneasy peace, but no real resolution of the issues that had started the war. Instead of international cooperation and peace, the 1920s and 1930s were an era of rising problems. Viewed through the communities frame, we can see this as a period in which democracy took a step backward, while racism and extreme nationalism came to the forefront. Then came the terror of the Second World War (1939– 1945) and the genocide known as the Holocaust. Victory for the Allies ended this war after five-and-a-half years of conflict. However, war—and even genocide—remain a part of the human experience still today.

How should we understand these thirty years or so of conflict? What lessons do they hold for us? This era and these experiences were so traumatic that they still hold a lot of meaning today. Films and TV series about the First and Second World Wars are still hugely popular. Politicians and protesters today often accuse each other in terms that originated in this era—calling each other “fascists” or even “Nazis.” In doing so, they are invoking the past, although not always in an accurate or useful way. To be sure, there’s much to learn from a careful study of this period. But what are those lessons?

The First World War

The First World War may be a tragic example of a war that didn’t have to happen, but it also may contain a warning about the way that nationalism can lead to disaster. In the first lesson in this unit, we begin by looking at the evidence and debate surrounding the origins of the First World War. Was it really just the result of an assassin’s bullet, publicly and dramatically finding its target in the Archduke in Sarajevo? Or was the conflict a result of longer, darker trends underneath the surface of the happy story we told ourselves.

Once we have explored how the war began, we can spend the second lesson of the unit understanding the experiences and outcomes of the war. We can think about the individuals who served, like the Indian soldiers serving Britain in the image above. Next, we’ll discuss how their experiences changed the way they saw the world around them. We also consider how whole societies were transformed by what was perhaps the first “total” war in history. It involved almost everyone in many of the countries that participated, even if they were not themselves combatants.

We’ll also see how the First World War led to massive events, like the civilian mass-murders made possible by modern weapons, as well as long-term changes like the Russian Revolution.

A period of peace, or the road back to war?

When the First World War ended in 1918, many people hoped that they could avoid another global conflict. Instead, just two decades later, an even larger and more devastating war broke out. What went wrong?

In the third lesson of this unit, we’ll try to understand how the Second World War could have happened. We see how a movement for international cooperation and peace briefly flourished in the 1920s but then quickly fizzled out. The treaty that ended the First World War harshly punished the losing side by taking land and collecting enormous fines. This created resentment and destabilized the global financial system. A great economic depression in the 1930s made things worse. But, most dangerous of all, was a loss of belief in democracy and international cooperation as ways to solve problems and make life better for people. As a result, extreme nationalism reemerged once again, and it was more powerful than before. It took many forms, including racism and antisemitism. But perhaps the most menacing element was the rise of fascism, an ideology that mixed extreme nationalism and racist ideology with a call for violence, action, and obedience.

Fascists and people with similar ideas emerged in many places, including the United States. They actually managed to take power in a few countries, in particular Italy, Japan, and Germany. In the 1920s, Japan began to take territory in nearby countries, mostly China, and the international community failed to stop them. In the 1930s, Fascists in Italy and Nazis in Germany began to invade their weaker and smaller neighbors in Europe and North Africa. Again, nobody was willing to stop them. Germany kept pushing the limits until, in 1939, Britain and France warned Germany not to invade Poland. When it did invade, Britain and France declared war, marking the start of the Second World War.

The Second World War

The war itself lasted more than five years and cost tens of millions of lives. Hardly any corner of the globe was untouched. In the fourth and final lesson of this unit, we will look at the events and experiences of this conflict. We’ll see how the world sort of organized into two sides, with Germany, Japan, Italy, and some smaller countries becoming known as the Axis powers. They fought against a vast alliance, sometimes called the Allied powers, that included Britain, France, the United States, the Soviet Union, and dozens of smaller states. These allies won, in the end. Their victory was partly due to larger numbers and economies, but their superior technology certainly gave them an edge as well. Humanity’s ability to kill reached new levels in this war, culminating in the nuclear bombs dropped by the United States on Hiroshima and Nagasaki, which forced Japan’s surrender and ended the war.

The Second World War was a collective human experience of devastation and terror. The war years allowed the Nazi party in Germany to carry out the largest planned mass murder of a group of people in world history—the Holocaust. Other states also carried out war crimes against civilian populations across wide regions of Europe and Asia. These atrocities may have been less planned and less deliberate than the Holocaust, but they were still horrific. Civilians were frequently detained during the war, even in the democratic Allied powers. The US government forcibly moved hundreds of thousands of Japanese-Americans to internment camps for the course of the war. In Britain, the government deported or detained thousands of Germans and Italians. The Second World War created millions of refugees, who still had no home or way to get home at the end of the war. And when the war ended in 1945, it wasn’t clear if the fighting was really over. The two countries who came out of the war the strongest—the United States and the Soviet Union—were deeply suspicious of each other.

Conclusion

Once again, as they had after the First World War, world leaders gathered together in 1945 to try to resolve these problems and save the future from any more global conflicts. As they did so, they wondered if they could do a better job than the previous generation of leaders. They promised: “Never again!” Never again would the horrors of world war and genocide be visited on humanity. They promised a better future. Those promises were still being made in the 1980s. As I reflect back on my teenage self, I wonder if I actually believed the narratives I was being taught. After all, my own family had lost many members to the Holocaust. So even though I was being taught a version of history where things always got better, my family history and their stories reminded me of just how bad the world could get.

1 But remember, many things do get better again. We keep reminding you that history isn’t just a long story of progress, but it isn’t all bad news, either.