The attack on Pearl Harbor was just Japan’s first move.  Within weeks, Japanese forces had taken Singapore, Hong, Kong, and the Netherlands' East Indies.  American installations at Guam and Wake Island also fell.  The Philippines held out longer, but this crucial American outpost would also be surrendered to the Japanese. 

For Americans, the Japanese advance was terrifying and formidable but somewhat illusory. American resources had not yet been mobilized for war—and when they were, policymakers decided to concentrate first on the war in Europe.  Japan’s early success was tied, to a certain extent, to the American belief that the Japanese were actually the weaker foe.  Once Germany was defeated, Japan would and could be dealt with. 

But the success of this strategy relied on certain key facts.  A few critical outposts must be retained.  The Allies needed to hang on to Australia so that they could reach the Japanese from the south.  And Hawaii could not be lost.  If this stepping stone to the Far East fell, American forces would have an almost impossible time reaching the distant enemy nation.  

Japan understood all this just as clearly, even more so after American planes hit Tokyo on 18 April 1942.  The Allies’ ability to hit them at home had to be reduced and therefore they set their sights on Australia and Hawaii.  

Coral Sea

To achieve the first goal, the Japanese navy resolved, in late April, to capture Port Moresby in New Guinea and Tulagi, one of the tiny Solomon Islands.  From these locations, Japanese bombers could reach Australia and bomb the Allied nation into submission.

The Americans knew what was happening; they had much earlier broken the Japanese code. They sent two aircraft carriers loaded with planes to preempt the Japanese attacks.  They arrived too late to prevent the invasion of Tulagi, but they were able to plant themselves in the middle of the Coral Sea in between Australia and New Guinea.  From there, the carriers would try to prevent the Japanese from landing at Port Moresby.  

The Japanese matched this move; they sent two carriers of their own into the Coral Sea.  On 7 May, these carriers sent 27 planes out on a risky nighttime mission to find and sink the American ships.  But nine were shot down by American Wildcats—two others were destroyed by the Yorktown when their pilots mistook the American carrier for one of their own in the darkness and tried to land. 

The next morning, the battle resumed.  The opposing fleets remained separated by hundreds of miles; in fact, this was the first naval battle in which the opposing ships never saw or fired on one another.  Instead, they sent wave after wave of aircraft to do their fighting.  

By the end of the day, the opposing forces had done roughly equal damage.  One American carrier was sunk—the Lexington—74 planes were also lost.  The Japanese lost a light carrier and 80 planes.  But the significance of the battle did not lie in the box score.  With his decimated fighter force unable to provide adequate protection for his remaining ships, the Japanese commander withdrew.  Japan’s attempt to take Port Moresby had been turned back.  Australia remained, at least for the present, under Allied control.

Midway

Despite their setback in the Coral Sea, the Japanese navy under Admiral Yamamoto embarked in June on the second part of their Pacific strategy—the capture of Hawaii.  Before Hawaii could be taken; however, Midway must be seized.  Located about 1000 miles west of Hawaii, an attack on the American naval installation there would achieve two things:  provide a valuable stepping stone to the larger prize of Hawaii and lure American  ships into a battle that would weaken the American forces needed to defend Hawaii. 

To accomplish these objectives, Admiral Yamamoto put together an enormous fleet and a complex plan.  To draw off American vessels, he ordered a largely diversionary attack against US forces in the Aleutian Islands off the coast of Alaska.  To provide warning of American ship movement, he placed subs close to the American fleet stationed at Pearl Harbor. Then he organized his force into three groups and steamed toward Midway.

American code-breakers gave the American commander in the Pacific, Admiral Chester Nimitz, advance forewarning of all this.  He therefore positioned three carriers, jammed with 233 planes, 300 miles outside Midway.  Somehow, these carriers managed to avoid detection as the Japanese fleet sailed past toward Midway. As a result, when Vice Admiral Nagumo launched his planes against Midway on 3 June, a large American force lay about 150 miles behind him. 

The Japanese first wave did considerable damage to the island base.  But believing a second attack was necessary, Nagumo ordered his planes armed with bombs, rather than torpedoes, to take out the airbase and planes still on the ground.   As a result, when the planes from the carrier group stationed outside Midway attacked Nagumo’s fleet, the Japanese were not prepared to retaliate.

Still, the Americans took a terrible hit.  All but four of the first 50 planes sent in the first attack waves were shot down.  But the fourth wave caught the Japanese by complete surprise, destroying three carriers.  The fourth, and last, in the Japanese battle group was destroyed the next day.

The American victory was reflected in part by the numbers.  Four Japanese carriers and 332 planes were destroyed.  The US lost no carriers and only 147 planes.  Strategically, Japan had failed to seize the island crucial to its larger objective of capturing Hawaii.  The United States had managed to stem the Japanese advance and secure their Pacific outposts.  Perhaps just as important, the Japanese military was dealt a devastating blow to its morale.  After Pearl Harbor it had believed itself invincible.  Commanders went into Midway confident that they would further cripple America’s Pacific defenses and neutralize the enemy that stood between them and their goals in Asia.  After Midway, the Japanese military was never quite the same.