Over the past century, there have been times when Americans showed they can unite to overcome formidable challenges: winning World II, sending men to the moon, bringing down Soviet communism. The coronavirus pandemic will not be remembered as one of them.

It's fair to say that we have done many things right, individually and collectively. Most Americans, most of the time, have abided by the counsel of public health experts that we wear masks, socially distance and avoid large indoor gatherings. Most governors and mayors have taken prudent steps to curb transmission of the virus. In all, we've done pretty well.

But pretty well is not good enough. On a final exam, getting most of the answers right can mean an F. Reality doesn't grade on a curve.

To date, more than 336,000 people have died of COVID-19, and things are getting worse, not better, with nearly twice as many deaths in December as in November.

The rollout of vaccines will eventually turn things around, but not before tens of thousands more people are dead.

Many of the deaths so far were inevitable, once this virus found its way to our shores. But many are the direct result of reckless, careless or uninformed choices that could have been avoided.

The failure started at the top, with President Donald Trump. Month after month, he insisted that the pandemic would soon be just a memory. March 6: "It'll go away." Oct. 24: "It is going away; it's rounding the turn." Who can forget his forecast of "packed churches" on Easter, or son-in-law Jared Kushner's prediction that by July, the country could be "really rocking again"?

The administration's false hopes were regrettable not just because they were wrong but because they promoted mistaken policies and reckless conduct. Many red-state governors refused to require masks in public, and others did so only after needless delays. Some Republican governors even took steps to block local governments from issuing such mandates.

The official resistance to basic precautions spurred widespread defiance. Anyone who has taken a trip by car can attest that an alarming number of people go into grocery stores, gas stations and motel lobbies without face coverings.

They are following the example of a president who was so contemptuous of caution that his White House became a cluster of infection. Trump also mocked mask-wearers and held mass gatherings that were perfectly crafted to spread the disease. A study by Stanford economists estimated that 18 Trump campaign rallies produced 30,000 additional cases of COVID-19 and 700 deaths.

But let's not put all the blame for these on him. Each of the people who attended those crowded events made the choice to risk getting the virus and then passing it on to people who chose not to attend. Trump was irresponsible, and so were they.

Even some officials who embraced essential public health measures, however, sabotaged the effort through their own selfishness. Chicago Mayor Lori Lightfoot got her hair styled when hair salons were closed by state order. California Gov. Gavin Newsom violated his own rules by attending a birthday party at a fancy restaurant. Denver Mayor Michael Hancock told his constituents not to travel for Thanksgiving, before flying off to see relatives.

One obstacle to universal cooperation is that many people who take risks don't get the virus, which encourages them to take more risks. Another is that most of us know someone who has gotten it and suffered no serious effects, which creates a false sense of security. If COVID were far more contagious and lethal — as Ebola is — Americans would have been more careful.

Self-discipline isn't easy in the absence of immediate, obvious dangers or rewards. But the fact that an obligation is hard is not a license to disregard it.

Even in places with tight restrictions, there is little enforcement, letting some people flout the most vital rules. The English writer G.K. Chesterton said: "The Christian ideal has not been tried and found wanting. It has been found difficult; and left untried." Too many of us have taken the same approach to the best practices for combating the coronavirus.

Huge numbers of people deserve credit for diligently striving to defeat the virus. But too many have been indifferent or rebellious. Americans like to think that as a nation we are capable of meeting any challenge. Looks like we've been fooling ourselves.

Steve Chapman blogs at http://www.chicagotribune.com/news/opinion/chapman. Follow him on Twitter @SteveChapman13 or at https://www.facebook.com/stevechapman13. To find out more about Steve Chapman and read features by other Creators Syndicate writers and cartoonists, visit the Creators Syndicate website at www.creators.com.