The Implications of Pearl Harbour and Japanese Loss in World War II

Prior to the Japanese attack on Pearl Harbour, the intelligence services of the United States received a significant number of Japanese plans. The vast quantity made it impossible for them to identify Japan's plan to attack Pearl Harbour as it resulted in a decoding delay. For that reason, the announcement that Japan was breaking off diplomatic relations with the USA did not emerge until just six hours before they attacked Pearl Harbour.

US intelligence services had assumed that an attack would be launched against the Dutch East Indies or the American bases in the Philippines, but Pearl Harbour was not predicted to be a possible point of attack.

The Japanese attack on Pearl Harbor had a significant impact on the foreign policy of the United States. 

US isolationism quickly ended as Americans could no longer claim that events in the wider world did not affect or concern them.

As the USA declared war on Japan, Hitler believed that Germany would be invincible with Japan as an ally and in return, Germany declared war on the USA, guaranteeing American involvement on the battlefields of Europe.

Nevertheless, there are a number of points of Japanese failure in the attack on Pearl Harbour.

• a number of American ships, including three aircraft carriers (USS Enterprise, USS Lexington and USS Saratoga) were at sea at the time and therefore escaped undamaged.

• The ships anchored in Pearl Harbor were in shallow water, so it was relatively easy for some of those that were less damaged to be salvaged and repaired

• The number of American deaths was far lower than Japan had envisaged, because most crewmembers were on shore leave at the time.

• The attack failed to destroy large supplies of oil, which were vital in supplying the USA’s WW2 war efforts.

• Despite the fact that it was seriously damaged, the Pacific Fleet of the United States was far from destroyed.

Impact on Japan

As a military dictatorship, changes in Japan is foreign policy and its relations with the international community by defiance of various treaties which it had signed resulted in its downfall.

It had ignored and withdrawn from the league of Nations, which it had been a co-founder of, and allied with the fascist regimes of Germany and Italy. They had mirrored their actions by attempting to expand their empire through military means. By doing so, Japan brought destruction upon themselves as close links with Nazi Germany simply brought them into conflict with Western democratic nations, such as Britain.

In the Sino-Japanese War, they had been involved in a war against an increasingly united China and received no benefit from it.

And As a result of their territorial conquests, Japan faced numerous wars with powerful nations.

Finally, by attacking Pearl Harbour, Japan now faced a new enemy—the United States of America—the most powerful nation on Earth, the nation with the strongest and largest economy and military.

The US Declaration of War

Japanese Military leaders had not only failed while planning the attack on Pearl Harbour, but had severely underestimated how quickly and what actions the United States would take in the wake of the attack.

On the 8th December 1941, the day following the attack on Pearl Harbour, both the United States of America and Great Britain declared war on Japan.

On December 10, Germany and Italy declared war on the U.S.

The End of World War II

Let’s skip ahead to July 16, 1945 which is when the United States secretly detonates the world's first atomic bomb in the New Mexico desert. 

On July 26th, the Allies issued the Potsdam Declaration which demanded the “unconditional surrender of all the Japanese armed forces.” If Japan failed to follow their demands, “the inevitable and complete destruction of the Japanese armed forces and just as inevitable the utter devastation of the Japanese homeland.” would proceed. However, Japan ignored their warnings, and on August 6th 1945, Enola Gay dropped an atomic bomb on the Japanese city of Hiroshima, which killed up to 146,000 people in total.

Despite some willingness within the supreme war council of Japan to accept the Potsdam Declaration, Japan continued to ignore the warnings and to an extent, the government seemed unaffected by the atomic bomb.

However, on the 8th of August , the USSR declared war against Japan, with Soviet forces attacking Manchuria the next day, rapidly overwhelming Japanese defences. 

On the 9th of August, the U.S. dropped a second atomic bomb on Nagasaki, killing up to 80,000.

Emperor Hirohito announced Japan’s surrender on August 15, 1945.