When the coronavirus emerged in China in January, the World Health Organization didn’t flinch in its advice: Do not restrict travel.

But what is now clear is that the policy was about politics and economics more than public health.

Public health records, scores of scientific studies and interviews with more than two dozen experts show the policy of unobstructed travel was never based on hard science. It was a political decision, recast as health advice, which emerged after a plague outbreak in India in the 1990s. By the time Covid-19 surfaced, it had become an article of faith.

“It’s part of the religion of global health: Travel and trade restrictions are bad,” said Lawrence O. Gostin, a professor of global health law at Georgetown University who helped write the global rules known as the International Health Regulations. “I’m one of the congregants.”