What America did to Japan in 1945 was a terrible thing. These days the United States and Japan are best friends, and we always will be best friends. We even share a love for baseball.

Wall Street Journal

OPINION

COMMENTARY

The Atomic Bomb Saved Millions—Including Japanese

An invasion would have meant massive casualties. War would have dragged on until 1947 or later.

By John C. Hopkins

August 5, 2020

The atomic bombings of Hiroshima and Nagasaki, 75 years ago Thursday and Sunday, respectively, are regarded with horror and regret. But not using the atomic bomb would have been far worse. The overall Japanese deaths attributed to the two bombs are estimated at between 129,000 and 226,000. A July 1945 U.S. government report estimated that invading the Japanese Home Islands would cost five million to 10 million Japanese lives.

The U.S. landing, planned for Nov. 1, 1945, was to be substantially larger than the 1944 Normandy landing in Europe. More than 156,000 Allied troops landed on D-Day. They suffered more than 10,000 casualties, including 4,400 killed in action. They faced 50,000 German troops. The invasion of Japan would have involved some 766,000 Allied personnel.

And it would have been harder than D-Day, which took the Germans by surprise. The Japanese had deduced both the approximate landing date (late October) and the landing beaches on Kyushu, the southernmost of Japan’s main islands.

Only after the war did the U.S. discover the magnitude of Japan’s preparation to defend against the invasion. In June 1945, U.S. intelligence estimated 350,000 Japanese troops would defend Kyushu. After the Japanese surrendered, the U.S. military demobilized some 784,000 men on Kyushu. In addition, there were some 575,000 Kyushu home-defense forces. Unlike the 3 to 1 ratio of Allies to adversaries at Normandy, the Japanese defenders would have outnumbered Allied troops in the initial assault landing.

The Japanese also were preparing more than 10,000 planes to make kamikaze attacks on the U.S. landing ships before they could discharge their troops. And Japan had almost five million soldiers and sailors still fighting across Taiwan, Korea, China, Manchuria and various Pacific islands.

Civilians would be mobilized, too. On April 20, 1945, the Japanese Imperial Army issued “The Decree of the Homeland Decisive Battle,” which proclaimed: “Every soldier should fight to the last . . . and our people should fight to the last person.” Every Japanese soldier and civilian—even women and children—was expected to die fighting.

The U.S. government estimated, based on the fierce Japanese resistance encountered on outlying islands, that the war would last another year and a half—through the spring of 1947. It expected between 1.7 million and four million Allied casualties, including 400,000 to 800,000 fatalities. (Between December 1941 and August 1945, the war in Europe and the Pacific had resulted in 407,000 U.S. deaths.)

Weather would have made matters still worse for the Allies. On Oct. 9, 1945, a typhoon packing 140-mile-an-hour winds struck what was to have been the U.S. invasion staging area on Okinawa. The damage to the invasion fleet and forces would have delayed the invasion by perhaps six months. On April 4, 1946, another major typhoon hit. It would have caused another delay. The Japanese would have many months to strengthen their defenses.

Meanwhile, the Soviet Union (which declared war on Japan on Aug. 8, 1945) was prepared to invade the Japanese northern islands from Manchuria. That would almost certainly have led to a Japan divided between a free South and a communist North. The Berlin Wall might have had a twin in Tokyo. The people of North Japan would have suffered for decades, like the people of East Germany and North Korea.

All this was averted. On Aug. 15, Emperor Hirohito announced Japan’s surrender. Japan faced a major famine during the winter of 1945-46, which the U.S. ameliorated by providing humanitarian shipments of more than 800,000 tons of food.

The Japanese losses from the atomic strikes were tragic. But their use prevented far more pain, suffering and death than it caused. The U.S. chose the lesser of evils.

Mr. Hopkins, a nuclear physicist, was an executive at Los Alamos National Laboratory, 1974-89.