Hollandia (now Sukarnapura), a major Japanese air and supply base, held two crucial advantages for the Allies. The port of Hollandia in Humboldt Bay was the best-sheltered anchorage along a lengthy stretch of the New Guinea coast, and the surrounding area had four airstrips. Together these assets could provide a major staging base for future operations in western New Guinea and the Philippine Islands. In addition, SWPA's intelligence determined that Hollandia was garrisoned only by a small force of 11,000 Japanese troops from the 6th Air Division, most of them service personnel. By attacking Hollandia, MacArthur could avoid potentially bloody battles to the east at Hansa Bay and Wewak, both of which were more strongly defended.
MacArthur and his staff were compelled to include a simultaneous attack at Aitape, 140 miles east of Hollandia. Airstrips there would provide a permanent staging area within range of Hollandia, enabling the Allies to seize command of the air. The Hollandia and Aitape invasions together required a flotilla of more than 200 ships and 80,000 personnel.
During late March and early April 1944, Allied pilots destroyed most of the 6th Air Division's aircraft, paving the way for the landing of ground troops on 22 April. At the same time, General Adachi Hatazo, commander of the Eighteenth Army headquartered on Rabaul, regrouped his battered forces near Hollandia. U.S. forces, meanwhile, carried out a remarkable counterintelligence scheme to divert Adachi. False radio transmissions, decoy raids, patrols, and bombing convinced the Japanese that an Allied assault at Hansa Bay was imminent.
The landing, dubbed Operation reckless, was entrusted to Lieutenant General Robert L. Eichelberger's I Corps. One regiment from the 24th Infantry Division went ashore at Tanahmerah Bay, and another regiment from the 24th Division and two regiments from the 41st Infantry Division landed at Hollandia about 25 miles to the east. Simultaneously, a regiment from the 41st Division and a regiment from the 32nd Infantry Division landed at Aitap, 125 miles to the southeast to secure a fighter strip. Their chief opposition came in the form of the marshy beaches themselves. Later that day, the 163rd Regimental Combat Team took Aitape against only limited resistance, demonstrating the effectiveness of the Hansa Bay ruse. With Aitape in hand, the ground forces at Hollandia trudged through trackless marsh and bog to encircle the three main Japanese airfields. Confusion, fear, and lack of weaponry prompted a large-scale Japanese retreat west.
Suppressing remaining resistance, U.S. forces secured Hollandia on 26 April 1944 only four days after the initial landings, although mop-up operations continued for several weeks. The most telling evidence of the Allied air attacks before the landings was the wreckage of more than 340 Japanese aircraft on Hollandia's runways. Allied casualties were 159 killed and 1,100 wounded. The Japanese lost 3,300 dead and 600 prisoners. At Aitape, all objectives were secured by 25 April at a cost of 3 American dead. About 600 Japanese were killed, and 27 were taken prisoner. Another 6,000 Japanese were either killed by units from the 24th Division or died from starvation and disease as they retreated from Hollandia to Wadke-Sarmi 140 miles to the west.
Operation reckless was a major triumph for MacArthur. It split the Japanese forces defending New Guinea in half, leaving the Eighteenth Army isolated in eastern New Guinea. It also gave MacArthur a superb base from which to increase the tempo of operations in the SWPA, and before long U.S. engineers had turned Hollandia into a vast complex of military, naval, and air facilities occupied by 140,000 men. John Kennedy Ohl and Bryan Joseph Rodriguez
Chwialkowski, Paul. In Caesar's Shadow: The Life of General Robert Eichelberger. Westport, CT: Greenwood Press, 1993.; Drea, Edward J. New Guinea. Washington DC: U.S. Army Center of Military History, 1993.; Drea, Edward J. MacArthur's
John Kennedy Ohl and Bryan Joseph Rodriguez