It was a measure of the Japanese strategic military ignorance, that they never understood how stupid their “Fortress Pacific”, strategy was.

The Japanese surveyed and deployed their armed forces along a roughly semi-circular ring of fortified islands running north to south from the Aleutian Islands to the Solomon Islands. Most of the bases were so far apart that they could not be regarded as mutually supporting. They could all be tactically by passed (to their flanks or rears) at will by surface, carrier air power, or submarine, naval power.

Then they trapped themselves in a self-inflicted catch-22; they deployed significant land forces on each island, or island group. The size of the garrisons’ required significant sealift capability be employed to resupply them.

Yet, the mobile naval forces of the US could immediately begin to interdict routine resupply of Japan’s island bases. Thus the bases began to be weakened by starving them of resupply. Immediately invalidating their utility. Without the forces Japan had deployed to the islands, ever being engaged, in their defense.

Cruelly, for Japan they never really grasped what a tactical military blunder they had made. Yes they were surprised. But neither during or after the war, did they grasp the enormity of the tactical blunder their island fortification strategy was.