We keep hearing that this is a war. Is it really? What helps to give the current crisis its wartime feel is the apparent absence of normal political argument. The prime minister goes on TV to issue a sombre statement to the nation about the curtailment of our liberties and the leader of the opposition offers nothing but support. Parliament, insofar as it is able to operate at all, appears to be merely going through the motions. People are stuck at home, and their fights are limited to the domestic sphere. There is talk of a government of national unity. Politics-as-usual has gone missing.

But this is not the suspension of politics. It is the stripping away of one layer of political life to reveal something more raw underneath. In a democracy we tend to think of politics as a contest between different parties for our support. We focus on the who and the what of political life: who is after our votes, what they are offering us, who stands to benefit. We see elections as the way to settle these arguments. But the bigger questions in any democracy are always about the how: how will governments exercise the extraordinary powers we give them? And how will we respond when they do?

Though the pandemic is a global phenomenon, its impact is greatly shaped by decisions taken by individual governments

These are the questions that have always preoccupied political theorists. But now they are not so theoretical. As the current crisis shows, the primary fact that underpins political existence is that some people get to tell others what to do. At the heart of all modern politics is a trade-off between personal liberty and collective choice. This is the Faustian bargain identified by the philosopher Thomas Hobbes in the middle of the 17th century, when the country was being torn apart by a real civil war.

As Hobbes knew, to exercise political rule is to have the power of life and death over citizens. The only reason we would possibly give anyone that power is because we believe it is the price we pay for our collective safety. But it also means that we are entrusting life-and-death decisions to people we cannot ultimately control.

The primary risk is that those on the receiving end refuse to do what they are told. At that point, there are only two choices. Either people are forced to obey, using the coercive powers the state has at its disposal. Or politics breaks down altogether, which Hobbes argued was the outcome we should fear most of all.

In a democracy, we have the luxury of waiting for the next election to punish political leaders for their mistakes. But that is scant consolation when matters of basic survival are at stake. Anyway, it’s not much of a punishment, relatively speaking. They might lose their jobs, though few politicians wind up destitute. We might lose our lives.

The rawness of these choices is usually obscured by the democratic imperative to seek consensus. That has not gone away. The government is doing all it can to dress up its decisions in the language of commonsense advice. It says it is still trusting individuals to show sound judgment. But as the experience of other European countries shows, as the crisis deepens the stark realities become clearer. Just watch the footage of Italian mayors screaming at their constituents to stay at home. “Vote for me or the other lot get in” is routine democratic politics. “Do this or else” is raw democratic politics. At that point it doesn’t look so different from politics of any other kind.

This crisis has revealed some other hard truths. National governments really matter, and it really matters which one you happen to find yourself under. Though the pandemic is a global phenomenon, and is being experienced similarly in many different places, the impact of the disease is greatly shaped by decisions taken by individual governments. Different views about when to act and how far to go still mean that no two nations are having the same experience. At the end of it all we may get to see who was right and what was wrong. But for now, we are at the mercy of our national leaders. That is something else Hobbes warned about: there is no avoiding the element of arbitrariness at the heart of all politics. It is the arbitrariness of individual political judgment.

Under a lockdown, democracies reveal what they have in common with other political regimes: here too politics is ultimately about power and order. But we are also getting to see some of the fundamental differences. It is not that democracies are nicer, kinder, gentler places. They may try to be, but in the end that doesn’t last. Democracies do, though, find it harder to make the really tough choices. Pre-emption – the ability to tackle a problem before it becomes acute – has never been a democratic strength. We wait until we have no choice and then we adapt. That means democracies are always going to start off behind the curve of a disease like this one, though some are better at playing catch-up than others.

Autocratic regimes such as China also find it hard to face up to crises until they have to – and, unlike democracies, they can suppress the bad news for longer if it suits them. But when action becomes unavoidable, they can go further. The Chinese lockdown succeeded in containing the disease through ruthless pre-emption. Democracies are capable of being equally ruthless – as they showed when prosecuting the total wars of the 20th century.

But in a war, the enemy is right in front of you. During this pandemic the disease reveals where it has got to only in the daily litany of infections and deaths. Democratic politics becomes a kind of shadow boxing: the state doesn’t know which bodies are the really dangerous ones.

Some democracies have managed to adapt faster: in South Korea the disease is being tamed by extensive tracing and widespread surveillance of possible carriers. But in that case, the regime had recent experience to draw on in its handling of the Mers outbreak of 2015, which also shaped the collective memory of its citizens. Israel may also be doing a better job than many European countries – but it is a society already on a permanent warlike footing. It is easier to adapt when you have adapted already. It is much harder when you are making it up as you go along.

In recent years, it has sometimes appeared that global politics is simply a choice between rival forms of technocracy. In China, it is a government of engineers backed up by a one-party state. In the west, it is the rule of economists and central bankers, operating within the constraints of a democratic system. This creates the impression that the real choices are technical judgments about how to run vast, complex economic and social systems.

But in the last few weeks another reality has pushed through. The ultimate judgments are about how to use coercive power. These aren’t simply technical questions. Some arbitrariness is unavoidable. And the contest in the exercise of that power between democratic adaptability and autocratic ruthlessness will shape all of our futures. We are a long way from the frightening and violent world that Hobbes sought to escape nearly 400 years ago. But our political world is still one Hobbes would recognise.

• David Runciman is professor of politics at Cambridge University