On September 6, 1941, the Japanese government decided to go to war with America. (Japan had been preparing for the possibility of war for several years.) Though the final decision to actually go to war was deferred, pending a possible diplomatic breakthrough, the machinery for war, especially in the Imperial Japanese Navy, was put in motion. In April 1942 Japan wanted to expand their defensive lines so they went east towards the island of Midway (1000 miles from Hawaii), they sent most of the imperial fleet to battle. That fleet was composed of four aircraft carriers, two battleships, thirteen cruisers, assorted submarines, transports and mine sweepers. "The Battle of Midway, 1942" EyeWitness to History, www.eyewitnesstohistory.com (2001). After that, an event known as the “Allied Code-Breaking” took place , Admiral Nimitz of the allied forces had his cryptanalysts had broken the JN-25 code. The US had been decoding messages since spring 1942 and they discovered that Japan’s objective was Midway. The American base at Midway started to send false messages saying that its water distillation plant had been damaged and that the base needed fresh water. The Japanese saw this and soon started to send messages stating that "AF was short on water”. AF was the name of the objective the Japanese had which was Midway. Commander Joseph J. Rochefort and his team at Station Hypo were able to determine that the attack was going to be on either the 4th or the 5th of June. As a result the Americans were able to enter the battle knowing when and where the Japanese were going to be and also with what force they were going to attack. The Japanese Naval Marshal General Isoroku Yamamoto considered that going to war with the United States was a “suicidal mission” and that he did not think that Japan could win such war.
Yamamoto had very complex plans before the battle; these could be considered optimistic because it believed that the USS Enterprise and the USS