'Cordial' was the US geographical rather than operational codename for Maloelap atoll in the central portion of the eastern Radak group of the Marshall islands group in the central Pacific (1941/45).
Part of the Marshall islands group, which the Japanese had taken from the Germans in World War I and for which they subsequently received a League of Nations mandate, Maloelap atoll is 98 miles (158 km) to the south of Majuro atoll and 70 miles (113 km) to the south-west of Wotje atoll, and was thus the main Japanese base closest to the Hawaiian islands group. Maloelap is about 30 miles (48 km) long on its north-west/south-east axis and between 8 and 15 miles (12.9 and 24 km) wide. The largest of its 71 islands and islets, which have an area of 3.8 sq miles (9.8 km˛) are located on the south-eastern end and include Taroa, the main island, on which the Japanese had in 1939 constructed a naval airfield with a pair of intersecting runways, one 1,420 yards (1300 m) long and the other 1,640 yards (1500 m) long, together with buildings and a radar installation. The Japanese also developed some port facilities, and the Japanese installations were protected from sea attack by 12 pieces of coast-defence artillery and from air attack by the 12 guns of two batteries of heavy anti-aircraft artillery.
On the outbreak of the Pacific War, some 21 Kawanishi H6K 'Mavis' flying boats of the Yokohama Air Group were based at Taroa, together with 12 Mitsubishi A5M 'Claude' fighters of the Chitose Air Group. The atoll was garrisoned by the 52nd Guard Force, which reached a peak of 2,940 naval and 389 army personnel under the command of Rear Admiral Shoichi Kamada.
The Americans did not discover the existence of the airfield until they undertook their carrier raids of 1 February 1942, when the airmen of the carrier force under the command of Vice Admiral William F. Halsey severely damaged the airfield, sank one transport vessel and one submarine chaser, damaged six other ships, and killed Rear Admiral Sukeyoko Yatsushiro, commander of the 6th Base Force.
After this, the history of the atoll and its Japanese base, which the Americans had considered to be the most important Japanese air base between Tarawa and Truk atolls, was essentially similar to that of the similar facilities on Wotje ('Creosote'), Jaluit ('Deadwood') and Mille ('Caddie'), being bypassed by the USA’s central Pacific offensive and left to 'wither on the vine'. Of the 3,097-man Japanese garrison (1,772 naval and 368 army personnel, and 957 civilians) only 1,041 survived the war, the rest having succumbed to air attack, starvation and disease.