Because of the rapid success in securing Kwajalein Atoll in the Marshalls, American planners decided to proceed with Operation catchpole to take Eniwetok. The assault force of just under 8,000 men centered on the 22nd Marine Regiment and soldiers of the army's 27th Division and attached troops. Brigadier General T. E. Watson had overall command, with Rear Admiral Harry W. Hill commanding the landing group. Unlike assaults in the Gilberts, adequate numbers of LVTs (landing vehicles, tracked) were available, and this operation saw the first extensive use of the DUKW amphibious trucks. Initially, fewer than 60 naval personnel defended Eniwetok Atoll, but on 4 January, Major General Bishida Yoshimi's 1st Amphibious Brigade, a veteran fighting unit, arrived, bringing total Japanese strength on the atoll to nearly 3,500 men.
The Eniwetok Expeditionary Group sortied from Kwajalein Lagoon on 15 February, covering the 326 miles to Eniwetok by two different routes. Engebi was the main U.S. objective because it had the atoll's only airfield. Including soldiers of the 27th Division and attached units, there were just under 8,000 men in the assault force. The invasion began at 8:44 a.m. on 17 February 1944, with the 1st and 2nd Battalions of the 22nd Marine Regiment landing on the southeastern beach. The attackers were supported by medium tanks of the 2nd Separate Tank Company. Initial Japanese resistance was light, and the only organized resistance occurred near Skunk Point. By 2:50 p.m., the island was declared secured, although mopping up continued into 18 February.
Operations against Parry and Eniwetok Islands would be more difficult. At 7:19 a.m. on 19 February, U.S. naval gunfire pounded Eniwetok Island, which was defended by 808 Japanese troops. The fire expended was minimal compared with that on the other islands, and few Japanese positions were damaged. At 9:17 a.m., the 1st and 3rd Battalions of the army's 106th Infantry Regiment landed. Things went badly from the start. The terrain prevented many of the LVTs from moving inland, and the Japanese covered the beach with automatic weapon and mortar fire.
At midday on 19 February, the Japanese launched a spirited counterattack with 300 to 400 men. The 106th was able to defeat the counterattack but at heavy cost. Shortly after 12:00 p.m., the 3rd Battalion, 106th Infantry was committed, but it failed to influence the course of the battle. An hour later, the 3rd Battalion, 22nd Marines was ordered ashore and directed to support the army's left flank. That night, the American units completed the capture of the western edge of the island and consolidated a defensive line near the beach.
The battle to secure the eastern side of Eniwetok was similar to the western battles. The 3rd Battalion, 106th Infantry landed on Yellow Beach 1 beginning at 9:17 a.m. on 19 February. Many of the Japanese beach defenses had been destroyed by naval gunfire, but once they were inland, the attackers discovered and were delayed by bunkers, pillboxes, and spider holes. Supported by carrier aircraft, the attacking troops secured the island on 21 February.
Parry Island was defended by 1,347 Japanese. Fortunately for the attackers, prisoner interviews and intelligence material captured on Engebi and Eniwetok revealed the Japanese defensive positions and provided U.S. planners a framework for a detailed preinvasion bombardment. Beginning at 10:00 p.m. on 20 February and continuing until the landing two days later, the battleships Tennessee, Pennsylvania, and Colorado, assisted by two heavy cruisers, pounded the island. Aircraft from three escort carriers also joined the assault.
Beginning at 9:08 a.m. on 22 February, the 1st and 2nd Battalions of the 22nd Marines landed abreast and were met by Japanese machine-gun and mortar fire at the water's edge. At 10:00 a.m., the Japanese opened up with 77 mm field guns, which were quickly silenced by naval gunfire. Meanwhile, the 3rd Battalion, 22nd Marines went ashore. The Marines fought to the ocean side of the island and then formed two lines. Each line battled to the opposite end of the island. By 7:30 p.m. that day, Parry was declared secure.
The battles to capture Eniwetok Atoll were the last major battles of the Eastern Mandates Campaign. Although planners expected this effort to be easy, stiff Japanese resistance from well-prepared positions slowed the progress of the U.S. forces. American casualties were 195 killed and missing and 521 wounded. Of the total Japanese force of some 3,431 men, only 64 prisoners were taken. No American ships were lost during the operation, although there was some damage from friendly fire. No Japanese surface ships contested the landing, but four submarines were sunk, along with a number of small supply ships and patrol craft. Troy D. Morgan and Spencer C. Tucker
Crowl, Philip A., and Edmund G. Love. The United States Army in World War II: The War in the Pacific—Seizure of the Gilberts and Marshalls. Washington, DC: U.S. Government Printing Office, 1955.; Heinl, Robert D., Jr., and John A. Crown. The Marshalls: Increasing the Tempo. Washington, DC: Historical Branch, U.S. Marine Corps, 1954.; Morison, Samuel E. History of United States Naval Operations in World War II. Vols. 2, 4, 5, 9, 10, and 11. Boston: Little, Brown, 1947–1952.; Sham, Henry I., Bernard C. Nalty, and Edwin T. Turnbladh. History of Marine Corps Operations in World War II. Vol. 3, Central Pacific Drive. Washington, DC: U.S. Government Printing Office, 1966.
Troy D. Morgan and Spencer C. Tucker