Richard Fernandez wrote 15 years ago in his essay “The Ten Ships”:
Admiral Nagumo launched his infamous attack on Pearl Harbor from a nameless patch of ocean 200 miles North of Oahu. But Admiral King had the sense to understand that the location itself had little significance. It was the Kido Butai, the ten carriers which made up the Japanese Fast Carrier force which momentarily occupied that ocean waste that he had to destroy. While the Kido Butai existed it could move across the vast spaces and attack at a point of its choosing. While it survived every patch of ocean was dangerous. Once it had been neutralized all the oceans of the world were potentially safe. As John Adams in his book If Mahan Ran the Great Pacific War wrote: “sink ten ships and win the naval war”. Both the Nihon Kaigun and the CINCPAC understood this. The entire purpose of subsequent American naval operations was to find and sink these ten ships; and the Nihon Kaigun’s subsequent efforts revolved around their attempt to preserve them.
Keeping that in mind, we can see that Midway Island itself was merely a plot device that existed to bring about the desired battle.