The world is at war. The enemy may be a tiny virus, but this string of ribonucleic acid has the effect of a large military force.

UN Secretary General Antonio Guterres called the coronavirus outbreak “the biggest challenge for the world since World War Two”. French President Emanuel Macron declared war on the virus. Upon his release from the hospital, UK Prime Minister Boris Johnson talked up the “national battle against coronavirus” in Churchillian language.

Equating the Covid-19 crisis to war is not just political rhetoric. As in wars, governments have seized immense powers to fight the ...