Thucydides, in his Peloponnesian war, narrates how, in 430 B.C. – the first year of the war – a deadly plague devastated the city-state of Athens. It killed one third of its population leaving a deep scar on its society and its democracy.

Today, a deadly pandemic is threatening the world and the unity of Europe. Struggling to recover from the Eurozone crisis of 2009 and the refugee-migration crisis of 2015, Europe is now overwhelmed by a pandemic crisis of almost biblical proportions; disasters come in triads, says an old Greek saying.

As countries are scrambling to deal with the immediate requirements of a colossal health emergency, an even greater threat looms on the horizon. Economists are warning us of the threat of an economic depression greater than that of 1929.

Both aspects of the crisis require a concerted and comprehensive pan-European response. If the response to the health crisis is the prologue, however, the future looks ominous.

Italy’s cry for help remained unanswered for weeks from the European Union member states, dealing a blow to European solidarity. We will always be haunted by the images of the military lorries carrying the dead of the city of Bergamo. The pandemic has led to the renationalization of the decision-making process, the return of national sovereignty and national borders. This is due to the lack of a European Health Agency and the fact that invoking state of emergency measures has remained a prerogative of the member states. Even in the American federal system, local governors are leading the fight. The federal government, however, even under the erratic leadership of Donald Trump, has also come to the rescue.

It is to the detriment of Europe that instead of a show of solidarity and a concerted and comprehensive European response, we see member states looking to China for health aid and equipment.

The Chinese state, after an initial phase of denial and cover-up that has worsened the spread of the virus across the planet, ultimately resorted to Draconian measures to contain the virus. Now, the regime has engaged in a public relations campaign to absolve itself of its grave responsibilities. Adding health aid to its Belt and Road Initiative, it is trying to exploit the absence of European solidarity to increase its influence in the south of Europe. It is also trying to project its efficacy in contrast to the slow and ineffective western democracies.

If European solidarity crumbled under the health emergency, the upcoming economic Armageddon will be the real test for Europe. The first signs are alarming. Germany, which has rightly criticized the Trump administration for a very narrow conception of the national interest and the dismantling of the liberal order, is doing exactly the same. As America is sacrificing the liberal multilateral order on the altar of America First, Germany is sacrificing European unity and solidarity on the altar of German fiscal responsibility and Germany First.

We often conceptualize the European experiment as a winding road full of turns, steep curves, and detours. A process of muddling through trial, error, and adjustment. This pandemic, however, is a defining moment for the “European polis” because it threatens to infect the European “body politic” irreparably. In political philosophy’s great tradition, the analogy between disease and civil disorder was proposed to encourage rulers to show foresight (Machiavelli) and reason (Hobbes) to prevent fatal disorder, as Susan Sontag had shown in her brilliant 1973 essay.

The challenge now for the European leadership is to act decisively, collectively, and expediently to prevent the recession from turning into a prolonged depression. The tragic loss of life should mobilize European leadership to take action to avert loss of livelihood that will affect European societies and democracies. As Mario Draghi, the man that kept Europe alive during the Eurozone crisis, wrote echoing Keynes: unforeseen circumstances require a change of mindset. Keynes had also stated that, “when the facts change, I change my mind.” This is a war and wars are financed by public debt. Otherwise, the cost of inaction will be devastating. And, this time, those in Europe that do not listen to reason and adapt to change will have no one to blame but themselves.

• Working Paper