One of the best teachers I’ve had was Dominic Lieven at LSE (here’s a review of a recent book of his on Russia vs Napoleon. Cool). He taught a course called the Politics of Empire and Post-Imperialism which was about the history and politics of empire, from early civilizations through to the present day and was awesome for a number of reasons, including surprising comparative historical nuggets such as “anyone who wants to study Stalin should spend a year on the Qing dynasty first.” His framework for thinking about politics was an adaptation of that developed by Michael Mann (not the director of Heat) in his series “The Sources of Social Power.” The Mann framework holds that history is broadly the story of overlapping power networks, characterised by political, economic, ideological and military influence. Lieven wanted to add two further power sources to this mix: demographics and geopolitics. In many ways I think these are the most interesting ones, and they’ve both come up in some recent articles.

Briefly, geopolitics says that Britain was the dominant world power for about a century following Napoleon’s ultimate defeat because its geographical position off the coast of Europe made it virtually unattackable and had also stimulated it to develop the world’s best navy. Thereafter, the United States took over because it was similarly isolated from major competitive powers by oceans but could also draw on continental-scale natural resources to fuel its growth, unlike Britain which had to rely on trade. This recent book uses a lot of similar “geography is destiny” ideas to tell a story of world history.

But demographics might be the more significant today. It’s the reason Western countries are running out of money: the population is getting old because the baby boomers didn’t have as many kids as their parents. The concept of a population explosion in the above-60 demographic is slightly bizarre, but the article argues it persuasively. It also explains why China and India are so significant: they have enormous populations that are in their most economically productive life stages. This is also why India has the long-term advantage: the one-child policy means that China will not replace its workforce as they retire. For Western countries with looming pension crises, the answer can only be importing more young people. I’d bet the Eastern European immigration controversies in Britain in the past few years will pale in comparison to what we see in the next 20 years.