What major events in World War II were affected by the attack on Pearl Harbor?
Almost all major events in World War II after December 7, 1941 were affected by the attack on Pearl Harbor. This is because the attack on Pearl Harbor (and Hitler’s ill-advised declaration of war on the US) got the United States into the war. US participation in the war had a tremendous impact on the war both in the Pacific and in Europe.
Until the attack on Pearl Harbor, the United States was not directly involved in WWII. American public opinion was strongly opposed to participation in the war. The US was giving “Lend-Lease” aid to the Allies, but it was not fighting. In December of 1941, England was the only power fighting Germany in Western Europe. The Soviet Union was fighting hard against the German invasion of the USSR, but the outcome of that campaign was very much in doubt.
When Japan attacked Pearl Harbor, everything changed. Now, the world’s biggest economy was in the war on the Allied side. Every battle in the Pacific was essentially caused by the attack on Pearl Harbor because that started the war in the Pacific. However, we must also note that the war in Europe was affected. Without the US, it is likely that there would have been no invasion of North Africa, no invasion of Italy, and no D-Day invasion of France.
The Japanese attack on Pearl Harbor got the US into the war. Therefore, every event that the US took part in, and even every event that was affected by the US being in the war, was affected by Pearl Harbor.