Recently I made a series for BBC Radio 4 called “Trump: The Presidential Precedents”. It told the stories of six previous US presidents who had won elections by promising to shake up a corrupt establishment and restore government by, or at least for, the little guy. From Andrew Jackson, the first westerner to win, to Ronald Reagan, who spoke of himself as the sheriff rounding up a posse to ride into Washington to rid the town of the bad guys, there was no shortage of examples of candidates posing as the outsider. As we all know, history doesn’t move in a straight line; there are disorientating changes of direction. In the US, the presidential election cycle encourages the current outsider to metaphorically wear the cap of liberty and pose as the redeemer of the people, even though others inevitably seize the liberator’s garb once the insurgent wears the crown. I ended the final programme with the thought that Donald Trump’s election was simply one of those periodic political lurches and that, just as every river has its bend, one day—and almost certainly in four or eight years—there would be a lurch back.

But maybe I was wrong. Maybe I was guilty of using historical context to minimize the unprecedented nature of the political moment we were in. When one listener told me that she’d found the series reassuring, I realized that the danger of reading the present through the lens of the past is that, unless carefully framed, it can convey a false sense that we know what’s coming next.

In particular, because in the West we’ve experienced more than half a century of relative stability, the sense that we’ve been here before can bias us towards an assumption of continuity. The perennial fault of generals is said to be they always want to fight the last war. If so, that’s a fairly commonplace psychological bias: most of us presume continuity. Even when culture and technology and deeply held assumptions shift around us, our brains try to fit them into old patterns. And so historians who point out similarities between the past and the present—as I did in my recent radio documentaries—may therefore be making it harder to know when we are in a moment of complete revolution or just a relatively familiar oscillation.

We often hear it said nowadays that the pace of change seems to have sped up. On the one hand, historians know that every generation thought this, but on the other, we also know that some generations objectively did deal with more turmoil than others. Maybe we are one of them.

When the Cold War structured international life, most people found it impossible to envisage how it could end. Few people now alive have lived without the institutions built in the aftermath of World War II to maintain international order – such as the UN, the IMF, the World Bank, or the EU; yet a long perspective suggests that just like every other attempt to maintain global stability in recorded history, they will not last forever. Pillars fall and worlds end.

Just because previous US presidents have been held to account, ultimately, by the rule of law, a free press and an independent Congress, that does not necessarily mean that the current one will be. Most of the time the people who tell you everything will probably revert to the mean are proved right, but sometimes they are spectacularly wrong.

The lesson is that history should never be a balm. Thinking historically should attune us to be more attentive to change rather than less. Understanding the world we live in right now means understanding how our assumptions, anxieties and material circumstances are different from last year, last decade and last century—noticing the differences that are both obvious and subtle.

This is a version of a piece I wrote for BBC World Histories Magazine.