Never again, Americans vowed after the Japanese attack on Pearl Harbor, 79 years ago this past Monday. Thoughtful people pause each Pearl Harbor Day to wonder whether we have forgotten the lesson we should have learned on Dec. 7, 1941.

Evidence Americans’ determination not to be victims of a surprise attack had flagged came on Sept. 11, 2001. That day, terrorists assaulted us, killing 2,977 people — far more than the 2,403 who perished at Pearl Harbor.

This Pearl Harbor Day, ought to have been occasion for realistic contemplation of whether “never again” means anything.

Our nation was dragged unwillingly into World War II by the attack on Pearl Harbor. Less than four years later, victory was ours — but at a cost of 405,399 deaths in the U.S. military. How many might have been avoided if we had been alert to the peril and better prepared to meet it?

We are in a new war, against a microscopic enemy far more deadly than foes we faced during World War II or those against whom we fight in the global conflict against violent extremism.

It took less than four years for Japan, Germany, Italy and their allies to kill 405,399 Americans.

It is probable that less than one year from its invasion of the United States, COVID-19 will have claimed that many American lives. By Friday, the death toll already had topped 278,000.

We were not ready for the pandemic. We were not prepared for it, despite years of warnings from scientists that it was only a matter of time until some “emerging disease” ravaged the world.

Will we, by this time next year, be proclaiming, “Never again?”

Will we mean it?