The struggle for Midway involved more than possession of an island. The Japanese First Air Fleet’s report, compiled after the battle, describes it as an American forward outpost protecting Hawaii, with added importance after the loss of Wake. The American defence plan expected an assault intended to capture the island and turn it into a base for operations against the Hawaiian area. M14 M26
Those records describe a Japanese assessment and an American expectation. Together they explain why a small place in a wide ocean could draw so much naval strength towards it. Air facilities, reconnaissance and the possibility of an enemy base gave the island a significance far beyond its size.
An island—and the fleet beyond it
The Japanese carrier force expected to attack Midway’s aircraft and support a landing. It also expected to be able to defeat an American carrier force that intervened. These were connected tasks: the island’s defences had to be suppressed, while the carriers retained the ability to fight at sea. M14 M06
The confidence behind that expectation is visible in the First Air Fleet report. Its account of the commander’s estimate says that a powerful American force centred on carriers was not believed to be operating nearby. It records an assumption that the operation had remained undiscovered. This is a report compiled after the battle, describing the force’s earlier assessment; it is not a surviving real-time view from every Japanese bridge. M14 M06
The plan therefore depended on more than striking power. It depended on assumptions about where the Americans were, what they knew and when they might react. An island attack and a fleet action could demand attention at the same time.
The American answer
Admiral Chester Nimitz’s Operation Plan 29-42, dated 27 May, prepared for an attack on Midway. It anticipated carrier strikes followed by a landing, and warned that American carriers discovered early might become the enemy’s principal target. Its predictions were estimates, not a transcript of Japanese orders. M26
The instructions to the American striking forces were nevertheless specific. They were to operate initially north-east of Midway and seek an advantage against Japanese carriers while those carriers’ aircraft were attacking the island. The Americans were preparing to exploit the very operation the Japanese intended to conduct. M26
Warning did not remove the need to search. Nor did knowing an attack was coming guarantee that American aircraft would find the enemy in time. Information could make an opportunity possible; ships and aircrews still had to turn it into one.
What could Nimitz afford to lose?
The plan ordered the defence of Midway and the infliction of maximum damage on the enemy. Alongside those aims it placed a restriction: the striking forces were to avoid an engagement likely to produce heavy losses among American carriers and cruisers. Preserving the fleet was part of the mission. M26
Even the force available was not yet entirely settled. The same document made Task Force 17’s availability as a unit dependent on the condition of USS Yorktown, and allowed for fresh instructions if she could not take part. A ship on a fleet list was not necessarily a ship ready to fight. M26
The headquarters record supplies the wider pressure. On 27 May, the CINCPAC running estimate described the strain of strategic defence with limited resources: Task Force 16 had rushed back from the South Pacific to meet the Midway threat and might soon be needed in the Coral Sea area again. More carriers and destroyers were needed to ease that burden. M19
Losing the American carriers would therefore have affected much more than the defence of one island. It would have reduced the forces available for the next emergency, wherever that came.
Before the outcome was known
Midway brought several questions together. Could the island hold? Could the Japanese carrier force defeat an American response? Could Nimitz damage that force without sacrificing the ships he needed for the wider war?
The answers would emerge from searches, attacks, damage control and decisions made with incomplete reports. To understand the victory—and what a Japanese victory might have meant—we first need to keep those different stakes in view.