The single biggest miscalculation was rushing to reopen the economy while the virus was still spreading at high rates through much of the country, experts say. The only way to reopen safely, epidemiologists said as far back as early April, was to “crush the curve” — to drive down the rate of viral transmission to the point that new infections were few and far between.

Many countries did just that. The United States did not follow the expert advice. Now, the curve is crushing America.

“We didn’t have the stick-to-itiveness, the determination, to carry through what we started in March, April and May, and now the virus is taking advantage of that,” National Institutes of Health Director Francis Collins said.

“If we’d had really strong guidance from local, state and national leaders, maybe we could have sustained the determination to get the curve all the way down to zero,” he said. “Now, we’re on the upswing, and I don’t quite see the top of the upswing yet.”