The United States' task one--a campaign in the Solomons to shield their tenuous lines of communication to the all-important major bases of Australia and New Zealand by seizing Tulagi--was envisaged by the Allied Combined Chiefs of Staff as early as April 1942. For a time it amounted to little more than an idea. But with the gradual repair of the damage done to the fleet at Pearl Harbor, and with the consolidation of the remnants of the Allied forces left in the South Pacific (SOPAC), and their reinforcement, the project began to appear feasible. It was duly christened WATCHTOWER. At this point, of course, Japan still had the superior fleet, but even the IJN could not be strong everywhere. And any battle in the Solomons would take place on a minor fringe of Tokyo's new empire. If everything went well, the Allies could expect to meet only minor opposition. But surprise would be essential. All other things being equal the enemy could concentrate forces there faster than the Allies could.
Partly as a result of the way intelligence was reported--these reports regularly omitted any reference to the presence of major combatants in or near Solomons waters, considering them to be only transients-- it was reasonably believed that IJN forces there consisted almost