“Every district, every lane, every village will be under lockdown,” Mr. Modi said in an address to the nation. He did not clarify how people would get food and other necessities, but vaguely mentioned government and civil society groups stepping in to help.

“If you can’t handle these 21 days, this country will go back 21 years,” he said. “The only option is social distancing, to remain away from each other. There is no way out to escape from coronavirus besides this.” He also pledged $2 billion for medical necessities.

Reminder: India’s caseload remains relatively low, with around 500 people infected. But experts worry that a disaster as bad as those in the U.S., Europe and China would be particularly catastrophic for India.

Reporter analysis: “Mr. Modi did not explain how the hundreds of millions of people who live in dire poverty will get food if they cannot go out,” said Vindu Goel, our tech reporter in Mumbai. It’s one of a host of unanswered questions our journalists will be following in this major shift.

He was hopeful, however, that this could change the country’s perception of the outbreak. “India has not taken coronavirus that seriously until this point, but the prime minister’s speech might be a turning point,” he said.