In the early morning on December 7th, 1941, Japanese fighter planes launched an attack on an American naval base at Pearl Harbor, Hawaii. The attack had left 1,000 wounded and 2,000 dead.
The US attempted to remain a neutral third party until Pearl Harbor, which ended all chances of diplomacy between America and Japan.
Prior to Japan’s assault on Pearl Harbor, American citizens wanted nothing to do with the war occurring overseas, as they saw no need for the US to get involved. Their opinion changed, however, after the attack and they supported President Franklin D. Roosevelt’s decision to declare war, which was approved by Congress.
America used a lend-lease program to supply weapons to the Allies, mainly Britain, while avoiding entering the war itself.
The US had built a large army via draft and had massive resources to support it. America was a production powerhouse that created huge amounts of ammunition, planes, cars, tanks, supplies, and more.
To assist their efforts in stopping Germany’s European takeover and prevent any more wrongs from occurring, the United States joined the Allied Powers.
The Allied Powers’ Operation Mincemeat was a hoax designed to trick the Nazis into moving their forces into Greece and Sardinia, which saved the lives of civilians.
By working together and sharing manpower, as well as supplies, the Allied Powers furthered their chances of success.
The Paris Peace Treaty was signed in 1917.
The United Nations was formed in 1945.
The San Francisco Peace Treaty was signed in 1951.
Cons:
The battle of Okinawa (Operation Iceberg) resulted in about 65,000 US deaths and about 75,000 Japanese deaths.
The attack on Pearl Harbor left 2,000 dead and 1,000 injured. The bombings of Hiroshima and Nagasaki resulted from 129,000 - 246,000 deaths and injuries.
The bombings of Hiroshima and Nagasaki hold one of the most non-combatant death totals in WWII, killing about 80,000 form the blast and countless more from radiation.
The bombing of Dresden killed around 35,000 to 135,000 civilians.
The bombings of Hiroshima and Nagasaki were highly unnecessary, Japan was already on the verge of surrender because of the losses in side battles. The bombings largely affected the Japanese civilians, not military personnel. The government covered up this mistake by saying that the bombs were needed to end the war, which is not true. President Truman justified this attack with this reason, "because of America's hatred of the Japanese and a desire for vengeance" hatred and vengeance is no reason to demolish two Japanese cities, kill hundreds of thousands of people and affect the land for hundreds of years to come."Hiroshima: Harry Truman on Trial."