The mask is the simplest and among the most effective weapons against the coronavirus in the public health arsenal. Yet from the start, America’s relationship with face coverings has been deeply fraught.

Faulty guidance from health authorities, a cultural aversion to masks and a deeply polarized politics have all contributed. So has a president who resisted role modeling the benefits of face coverings, and who belittled those who did.

The result, experts say, is a country that squandered one of its best opportunities to beat back the coronavirus pandemic this spring and summer. In the process, the United States fell far behind other nations that skipped the fuss over masks, costing lives and jeopardizing the recovery heading into the fall.