The objective of the maneuver was Guadalcanal, a small wet island with rugged terrain in the Solomon Islands, in the south Pacific. Despite the poor appearance of the island, it was nonetheless an exceptional strategic position for whoever owned it. At the beginning of May 1942, units of the Japanese army had simultaneously occupied Guadalcanal and the small neighboring island of Tulagi, an excellent anchorage from which the whole sector could be controlled. But it was only in June that Allied observers reported that some 3,000 troops had come from Tulagi to begin construction of an airstrip at Guadalcanal.
Located on one of the few flat terrains in the entire archipelago, the Henderson Field runway immediately presented a very serious strategic threat to the Allies. From there, enemy air forces could have control of the skies over the approaches to Australia from the United States. This contributed to isolating this continent and preventing it from forming the basis of future Allied operations in the Pacific. It was obvious that this situation would be intolerable. But Admiral King, the new Chief of Naval Operations for the United States Navy, insisted that simply destroying enemy installations would not be enough. He succeeded in convincing the Pentagon that the Solomon Islands should be off limits to the Japanese.
As a result, the 1st Marine Division, reinforced by commando units and paratroopers, was designated for this mission. Theoretically the Division was at full war strength; in reality it was an amalgam of many young recruits without experience of seasoned veterans. She left her base in North Carolina at the end of May 1942 under the orders of Major General Vandegrift. The latter learned on June 25 that his men were to go into line on August 1. By that date, half of the squad had still not reached their assembly point in New Zealand.
At sea, things were not much better.The cruiser squadron was made up of the Australian Hobarts , Canberra and Australia and the Americans Chicago and San Juan escorted by nine destroyers. She was commanded by Rear Admiral Crutchley, of the Royal Navy. There were also Vice Admiral Fletcher's aircraft carriers, the Saratoga, the Wasp and the Enterprise, pr Hosted by battleship North-Carolina. Neither these ships nor those of Rear Admiral Turner, commanding the South Pacific Amphibious Force, had ever operated together...