The Passing of the Generation that Remembers the Last World War Makes the Next One More Likely

In March, as President Biden was facing pressure to intensify U.S. involvement in Ukraine, he responded by invoking the specter of World War III four times in one day.

“Direct conflict between NATO and Russia is World War III,” he said, “something we must strive to prevent.” He underscored the point hours later: “The idea that we’re going to send in offensive equipment and have planes and tanks and trains going in with American pilots and American crews — just understand, and don’t kid yourself, no matter what you all say, that’s called World War III, OK?”

More than any other presidential statement since Sept. 11, 2001, Mr. Biden’s warning signaled the start of a new era in American foreign policy. Throughout my adult life and that of most Americans today, the United States bestrode the world, essentially unchallenged and unchecked. A few years ago, it was still possible to expect a benign geopolitical future. Although “great power competition” became the watchword of Pentagonese, the phrase could as easily imply sporting rivalry as explosive conflict. Washington, Moscow and Beijing would stiffly compete but could surely coexist.

How quaint. The United States now faces the real and regular prospect of fighting adversaries strong enough to do Americans immense harm. The post-Sept. 11 forever wars have been costly, but a true great power war — the kind that used to afflict Europe — would be something else, pitting the United States against Russia or even China, whose economic strength rivals America’s and whose military could soon as well.

This grim reality has arrived with startling rapidity. Since February, the war in Ukraine has created an acute risk of U.S.-Russia conflict. It has also vaulted a Chinese invasion of Taiwan to the forefront of American fears and increased Washington’s willingness to respond with military force. “That’s called World War III,” indeed.

Yet how many Americans can truly envision what a third world war would mean? Just as great power conflict looms again, those who witnessed the last one are disappearing. Around 1 percent of U.S. veterans of World War II remain alive to tell their stories. It is estimated that by the end of this decade, fewer than 10,000 will be left. The vast majority of Americans today are unused to enduring hardship for foreign policy choices, let alone the loss of life and wealth that direct conflict with China or Russia would bring.

Preparing the country shouldn’t begin with tanks, planes and ships. It will require a national effort of historical recovery and imagination — first and foremost to enable the American people to consider whether they wish to enter a major war if the moment of decision arrives.