The publisher of the Japanese translation of Ages of Discord (about to be published) requested a foreword, which presented me with a welcome opportunity to review how this book has fared, and to place it within my overall—long-term—research program attempting to understand the causes of recurrent waves of social and political instability that afflict all complex human societies organized as states. What follows is a lightly edited version of this foreword.

The story begins more than 20 years ago.  At that time, my colleagues and I had made substantial strides in understanding past crises—the Age of Revolutions during the long nineteenth century, the General Crisis of the seventeenth century, the late Medieval crisis. Our research also reached back in history to the crises of Antiquity. This work was eventually summarized in Secular Cycles, co-authored with Sergey Nefedov and published by Princeton University Press in 2009.

But even before the publication of Secular Cycles, as I gave research talks in various academic departments on this topic, I was almost invariably asked: so, where are we in the cycle? For awhile I resisted such inquiries, answering that I wished to keep my focus on past societies in order to avoid entering the minefield of contemporary contentious politics. But at some point repeated questions reached a critical mass. I decided to investigate how well the theory developed for pre-industrial states and empires would fare when applied to contemporary societies, which have clearly evolved a lot during the past two centuries. A natural focus of my investigation was the United States, a society which I knew from the inside.

Collecting the data needed for a structural-demographic “diagnosis” is a lot of work, and it took a few years before the general pattern started to emerge. But what I saw, frankly, shocked me. It turned out that general structural-demographic theory was quite applicable to the United States—after making relatively obvious adjustments, mostly taking into account the technological effects of the Industrial Revolution. But what was disturbing was that the data indicated that we were well along the road to political disintegration. The structural factors undermining social stability in past societies—popular immiseration, elite overproduction, and state fragility—were all trending in negative directions in the early twenty first century America.

In January 2010 a top science journal, Nature, asked “a selection of leading researchers and policy-makers where their fields [would] be ten years from now.” I decided to use this opportunity to publish a scientific prediction stemming from this structural analysis. In my “2020 Vision” I wrote, “The next decade is likely to be a period of growing instability in the United States and western Europe” and then briefly explained the empirical basis for this forecast. My goal was not to predict the future—I don’t believe that the future can be predicted with any accuracy. Instead, I aimed to subject the structural-demographic theory to a rigorous empirical test. If this prediction turned out to be incorrect, then subsequent analysis would tell us how the theory needs to be improved.

Unfortunately, the prediction turned to be disastrously correct. Of course, nobody in 2010 could know about the 2016 presidential election, won by Donald Trump, the COVID-19 pandemic, or the death of George Floyd on May 25, 2020. Such “triggers” of instability are inherently unpredictable. But at the more fundamental level, the structural drivers of instability continued to develop in the ways that were predicted by the theory. As I gave talks at academic departments between 2010 and 2020, the final slide of my presentation stated that we were still on track for a 2020 crisis.

In early 2020 my colleague Andrey Korotayev and I revisited the prediction made ten years before, and looked at various quantitative measures of instability in major Western countries. We discovered that incidence of anti-government demonstrations and violent riots had been declining prior to 2010, but this trend was reversed after 2010.

We submitted the article that presented this analysis to a scientific journal in the Spring of 2020. Then, as the article was undergoing review, the surging COVID-19 pandemic and the death of George Floyd at the hands of the Minneapolis police delivered a tremendous shock to the U.S. political system, triggering an explosion of nationwide, months-long series of urban protests. The “Turbulent Twenties” have arrived.

How does Ages of Discord fit in this story? The opinion piece, published in Nature in 2010, was very short and could only sketch out the causal factors pushing America into crisis. In the years after 2010 I also published several academic papers that fleshed out the details. But in order to be convincing, I needed to bring together different strands of this research. In particular, I had to integrate theory (and mathematical models that made it concrete) with data on long-term social, economic, demographic, and political dynamics in America, 1780–2010. This required a book-length treatment and the result was Ages of Discord.

As you read Ages of Discord, keep in mind that it was published in 2016, months before Donald Trump was elected U.S. president and years before the start of the Turbulent Twenties. The book focuses on structural causes—hidden forces that have been pushing America to the brink of civil war (and now maybe beyond). While no scientific theory is 100 percent correct, the disastrous success of the prediction made in 2010 tells us that the structural-demographic model is a useful way to look beyond surface events and to gain a deep understanding of what is happening in America. Keep in mind, also, that the theory is general. All complex societies organized as states are vulnerable to the three forces of instability—immiseration, elite overproduction, and the decline of state power. This may sound like a pessimistic conclusion, but my take is different. As solid scientific understanding of why ages of discord happen becomes better, we should be able to “engineer” our societies to avoid the extreme, most negative outcomes.