The Pacific theater of WWII began with the attack on Pearl Harbor,
7 December 1941. I think that is the date.
The Pacific theater was a long struggle for the USA, but, it had many victories along the way. The real casualties would come when the allied forces would enter Japan. They were confident they would win, but, there would be enormous costs in doing so.
The decision that launched a nuclear strike on Japan became clear when Hiroshima burned into oblivion on 6 August 1945.
That is a long time to be at war before a nightmare landed in Japan. Nearly four years of war and the number of battles in the Pacific was enormous.
Attack on Pearl Harbor
Fall of the Philippines and Dutch East Indies
Soloman Islands and New Guinea Campaign
Battle of the Coral Sea
Battle of the Aleutian Islands
Battle of Midway
and finally Japan
The USA has a great military. It battles relentlessly until the war is won. But, it seems as though the military is forgotten when all Americans think about is the nukes. The USA has always had incredible forces and that is excluding nukes. It is the soldier and the love of family and country that built the USA military not some plane over Japan.