The exercises anticipated several failures that have played out in the management of COVID-19, including leaky travel bans, medical-equipment shortages, massive disorganization, misinformation and a scramble for vaccines. But the scenarios didn’t anticipate some of the problems that have plagued the pandemic response, such as a shortfall of diagnostic tests, and world leaders who reject the advice of public-health specialists.

Most strikingly, biosecurity researchers didn’t predict that the United States would be among the hardest-hit countries. On the contrary, last year, leaders in the field ranked the United States top in the Global Health Security Index, which graded 195 countries in terms of how well prepared they were to fight outbreaks, on the basis of more than 100 factors. President Donald Trump even held up a copy of the report during a White House briefing on 27 February, declaring: “We’re rated number one.” As he spoke, SARS-CoV-2 was already spreading undetected across the country.

Now, as COVID-19 cases in the United States surpass 4 million, with more than 150,000 deaths, the country has proved itself to be one of the most dysfunctional. Morhard and other biosecurity specialists are asking what went wrong — why did dozens of simulations, evaluations and white papers fail to predict or defend against the colossal missteps taken in the world’s wealthiest nation? By contrast, some countries that hadn’t ranked nearly so high in evaluations, such as Vietnam, executed swift, cohesive responses.