In my thesis, I will look into Operation Downfall the cancelled invasion of the Japanese Empire by the United States and its allies. I will show the plans they made in a detailed manner, the different phases of the invasion that was considered, and what they expected the enemy’s defensive plans to look like. I will argue that it was the right choice that the United States found a different solution to end the Second World War, because just how devastating it would have been if Downfall had actually happened not just to the defenders, but to the Americans as well.