This year marks the 75th anniversary of the December 7, 1941, Japanese surprise attack on Pearl Harbor that killed more than 2,400 Americans.

President Obama is visiting Hiroshima this week, the site of the August 6, 1945, dropping of the atomic bomb that helped end World War II in the Pacific Theater. But strangely, he has so far announced no plans to visit Pearl Harbor on the anniversary of the attack. The president, who spent much of his childhood in Hawaii, should — given that many Americans have forgotten why the Japanese attacked the United States and why they falsely assumed that they could defeat the world’s largest economic power.

Imperial Japan was not, as often claimed, forced into a corner by a U.S. oil embargo, which came only after years of horrific Japanese atrocities in China and Southeast Asia. Instead, an opportunistic and aggressive fascist Japan gambled that the geostrategy of late 1941 had made America uniquely vulnerable to a surprise attack.

By December 1, 1941, Nazi Germany, Japan’s Axis partner, had reached the suburbs of Moscow. Japan believed that the German army would soon knock the Soviet Union out of the war.

Japan had also hedged its bets by signing a nonaggression pact with the Soviets. Japanese leaders assumed that even if communist Russia survived, Japan could avoid a costly land war on its rear flank. The U.S., not Japan, would likely have a two-front war.

By 1941, the Netherlands, France and Belgium had all been defeated and occupied by the Third Reich. Only the British remained of the original European anti-Axis allies, and London had been under constant aerial assault by the German Luftwaffe during the Blitz. Japan figured that Germany and Italy might soon win the war and wished to pile on before it ended.

Japan had calculated that all of Europe’s resource-rich Pacific and Asian colonies were now orphaned and up for grabs. By starting a Pacific war and knocking out the U.S., Japan could get its hands on the resources necessary to fuel its war machine.

British-held Singapore and the American bases in the Philippines were isolated and poorly defended. And they would be completely cut off once the U.S. Seventh Fleet and air arm were neutralized at Pearl Harbor.

Starting a war in the Pacific meant the Japanese would have easy access to huge supplies of oil, rubber, rice and strategic metals for their newfound mercantile empire, the Great East Asia Co-Prosperity Sphere.

The U.S. also had lost military deterrence. The Japanese had watched carefully as America did little to help its two closest allies: France and Great Britain. The former was easily overrun by the Nazis, the latter bombed unmercifully.

While the United States had belatedly built up its fleet and started rearming by 1941, its military was still woefully ill-equipped to fight a two-front global war. Japan logically figured that Germany and Italy would tie down the United States in Europe, while Japan systematically finished off any American warships that had escaped the Pearl Harbor wreckage.

In key categories such as fighter aircraft, torpedoes, night gunnery and destroyers, the Japanese were more formidable than the U.S. military in 1941.

Finally, a number of Japan’s most accomplished officers and diplomats had visited or studied in the U.S. in the pre-Depression boom years — among them Foreign Minister Yosuke Matsuoka, Admirals Isoroku Yamamoto and Tamon Yamaguchi, and General Tadamichi Kuribayashi. While they all had been impressed with U.S. industrial power, they nevertheless had developed contempt for American popular culture, finding it frivolous and fueled by Roaring Twenties affluence and leisure.

Many Japanese strategists had assumed that the U.S. never again would wish to endure a world war, and would prefer to negotiate rather than fight to the finish. Such assumptions proved false.

After Pearl Harbor, the United States went into a rearmament frenzy the likes of which had never been seen in history. America produced more airplanes and ships than all World War II powers combined. The U.S. military grew to 12 million soldiers.

American military leadership in the Pacific — led by Admirals William Halsey Jr., Chester Nimitz and Raymond Spruance, along with Generals Curtis LeMay and Douglas MacArthur — proved far more skilled than their Japanese counterparts. And the American soldier, sailor, airman and Marine, after a bruising learning experience in early 1942, proved every bit as ferocious as veteran Japanese fighters.

The road to Hiroshima and the massive loss of life in the Pacific was paved by unprovoked Japanese aggression at Pearl Harbor. Americans and their president should remember the lessons of that surprise attack 75 years ago this year.

© 2016 TRIBUNE CONTENT AGENCY, LLC.