A mainland invasion could have resulted in millions of Japanese deaths—and that's not counting civilians

In 1945, Paul Fussell, was a 21-year-old second lieutenant who'd spent much of the previous year fighting his way through Europe

writes the Wall Street Journal.

At the time of Hiroshima, he was scheduled to participate in the invasion of the Japanese mainland, for which the Truman Administration anticipated casualties of between 200,000 and one million Allied soldiers. No surprise, then, that when news of the bomb reached Lt. Fussell and his men, they had no misgivings about its use:

"We learned to our astonishment that we would not be obliged in a few months to rush up the beaches near Tokyo assault-firing while being machine-gunned, mortared, and shelled, and for all the practiced phlegm of our tough facades we broke down and cried with relief and joy. We were going to live."

Mr. Fussell was writing about American lives. What about Japanese lives? The Japanese army was expected to fight to the last man, as it had during the battles of Iwo Jima and Okinawa. Since the ratio of Japanese to American combat fatalities ran about four to one, a mainland invasion could have resulted in millions of Japanese deaths--and that's not counting civilians. The March 1945 Tokyo fire raid killed about 100,000; such raids would have intensified had the war dragged on. The collective toll from the Hiroshima and Nagasaki bombings is estimated at between 110,000 and 200,000.

Nuclear weapons are often said to pose a unique threat to humanity, and in the wrong hands they do. But when President Truman gave the go-ahead to deploy Fat Man and Little Boy, what those big bombs chiefly represented was salvation: salvation for young Lt. Fussell and all the GIs; salvation for the tens of thousands of Allied POWs the Japanese intended to execute in the event of an invasion; salvation for the grotesquely used Korean "comfort women"; salvation for millions of Asians enslaved by the Japanese.

Not least, and despite the terrible irony, the bombings were salvation for Japan, since they prompted Emperor Hirohito to intervene with his bitterly divided government to end the war, thus laying the groundwork for America's beneficent occupation and the country's subsequent prosperity. To understand the roots of modern Japan's pacifist mentality, so at variance with its old warrior culture, one need only visit Hiroshima's peace park.

More thoughts on Hiroshima…