The Pacific War will be covered in a series consisting of nine parts. Our team will publish an article for each part. This part is the second of a total of nine episodes.
Prelude to War: The Attack on Pearl Harbor
Japan’s Surprise Attack and America’s Counterattack
Naval Confrontation and Japan’s Initial Strategy
So, Japan decided to go to war with the United States, but in reality, the vast Pacific Ocean lies between the two nations. Naturally, the first critical factor becomes naval battles between their fleets. No matter how powerful the U.S. military was, if the navy protecting the ships transporting troops couldn’t function effectively, they wouldn’t be able to attack Japan. With this in mind, Japan’s initial strategy was:
“Gradually wear them down, then settle it near Japanese waters.”
Since the U.S. fleet would depart from distant locations like the American mainland or Hawaii, Japan planned to turn the ocean between the two countries into a battlefield. They would continuously attack with naval vessels other than its main battleships (smaller or secondary vessels), wearing down the U.S. fleet.
By the time the Americans reached Japanese waters, their fleet would be battered and exhausted. At that point, Japan would launch a full-scale assault with their powerful main fleet, centered around battleships, to annihilate the enemy. Sounds like a solid plan, right? However, this strategy was essentially a carbon copy of one Japan had used 36 years earlier in the 1905 Russo-Japanese War during the Battle of Tsushima.
※ We’ll cover the Russo-Japanese War in detail separately.
Yamamoto’s Opposition and New Proposal
Japan had won a war once before using this approach in the Russo-Japanese War, so they thought, “We won with this strategy before, so it’ll work again this time.” Most of the Japanese military agreed with this plan.
However, one man objected, saying, “How long are we going to keep repeating this outdated tactic?” That man was Yamamoto Isoroku, a prominent military figure.
Yamamoto’s radically different perspective stemmed from his time studying abroad in the United States during his youth. The Japanese Navy had a program to send promising officers overseas, and through this, Yamamoto lived and studied in the U.S. before the war.
There, he witnessed a highly advanced America, far ahead of Japan—skyscrapers lining the streets, countless cars buzzing around—a futuristic urban landscape unimaginable in Japan at the time. This experience left him awestruck.
The Birth of the Pearl Harbor Attack Plan
Having seen America firsthand, Yamamoto concluded, “There’s no way we can beat this country head-on. Are we seriously trying to win with a 36-year-old strategy? That’s insane.” His alternative was a “short-term decisive strike.”
The idea was to deliver a devastating blow at the outset of the war and then immediately secure a promise to end the conflict on terms favorable to Japan. Acknowledging that Japan could never win a prolonged fight against the U.S., he aimed to land a massive first strike, inflict heavy damage, and instill in America the belief that “continuing this war with Japan isn’t worth it.”
To achieve this, Yamamoto targeted the Pearl Harbor base in Hawaii. Pearl Harbor housed facilities for repairing ships, airfields for launching planes, and oil reserves for fuel supply. If Japan could thoroughly destroy Pearl Harbor at the war’s outset, the U.S. would lose Hawaii as a staging ground. This would push the U.S. Navy’s base of operations back to the mainland, leaving them without a foothold near Japan and tipping the war heavily in Japan’s favor.
Yamamoto’s Psychological Warfare and Military Discord
Yamamoto also predicted that a major strike on Hawaii would spark anti-war sentiment among the American public. Up until then, Americans had experienced wars, but those conflicts happened far away—across the Pacific in China or across the Atlantic in Europe. Hawaii, though distant from the mainland, was still U.S. territory.
An attack on Hawaii would feel like an attack on American soil itself. Yamamoto foresaw that a fierce battle on their own land would make Americans realize, “War directly threatens our way of life,” fostering a growing anti-war movement within the U.S.
Yamamoto's letter at the time
His plan was to dominate the Pacific with a decisive strike on Hawaii right after the war began, while simultaneously stoking anti-war sentiment in the U.S. to create a situation where America couldn’t continue fighting. This, he believed, would force the U.S. to agree to end the war on Japan’s terms—it was the only path to victory he envisioned.
However, Yamamoto’s proposal wasn’t easily accepted. As mentioned earlier, most military leaders favored reusing the successful Russo-Japanese War strategy. The Pearl Harbor plan, being entirely new, was criticized as “a gamble” and “speculative,” facing relentless opposition from the military establishment.
But Yamamoto was unwavering, convinced that “the only way to defeat America is through the Pearl Harbor attack.” He meticulously incorporated expert opinions into the plan, giving him absolute confidence.
Execution and Results of the Pearl Harbor Attack
Ultimately, the military gave in to Yamamoto’s passion, and the Pearl Harbor attack, perfected under his leadership, was set in motion. Japan’s first strike occurred almost simultaneously with—or slightly before—their declaration of war on the U.S. government.
In the early hours of December 7, 1941, they stealthily positioned their fleet near Pearl Harbor and launched the attack either at the same moment as or just before the declaration. Japan didn’t want to give the U.S. any time to prepare.
Whether this approach was justifiable has been debated even after the Pacific War ended, but the effect was undeniable. Out of the U.S. Navy’s eight battleships, Japan sank four and heavily damaged the other four.
The Japanese attack force then returned to Japan with minimal counterattacks from the U.S. Japan had scored a major victory at the war’s outset and returned unscathed. “Great job! The Pearl Harbor attack was a huge success!”—or was it?
Failure Within Success
As stated earlier, the true goal of the Pearl Harbor attack was to deal a blow so severe that the U.S. would lose the will to continue the war—not just to return triumphantly after a successful raid.
While Japan’s attack undeniably damaged the U.S. fleet, it was far from a total destruction of Pearl Harbor. The docks for ship repairs and the fuel tanks for ships and planes were left largely untouched. In other words, Pearl Harbor remained fully functional as a U.S. military base.
This half-baked result stemmed from Yamamoto’s vision not being fully communicated throughout the military. He had convinced the top brass to approve the attack, but his intent didn’t trickle down to the troops on the ground.
Many in the military still clung to Russo-Japanese War-era thinking, believing, “The Pearl Harbor attack is just to reduce the enemy fleet; the real victory will come by defeating them near Japanese waters.”
America’s Unity and the War’s Turning Point
According to Yamamoto’s strategy, the fleet should have been ordered to attack again after returning from the initial strike. However, a fleet commander who didn’t fully grasp Yamamoto’s intent feared U.S. retaliation and ordered a withdrawal instead. Thus, the Japanese fleet returned home triumphantly without achieving its ultimate objective.
Moreover, the attack failed to sap American morale as intended. This was because U.S. President Franklin Roosevelt outmaneuvered Yamamoto. While Yamamoto hoped to ignite anti-war sentiment, Roosevelt turned it against him.
In short, the Pearl Harbor attack united the American people. Tactically, it was a great success, dealing a heavy blow to a formidable foe. Strategically, however, it failed to achieve any of its original goals.