A Division At War — Part I
losses small . Not only had MacArthur set up a great anchorage and base for future operations , he had also bypassed and isolated an entire Japanese army . Half of the 32nd garrisoned Aitape and Hollandia , while the rest essentially became a theater reserve . A few months later , they reentered the fight .
The Japanese Eighteenth Army found itself in a precarious position after the US landings . Cut off , they had no hope for reinforcement or resupply . US naval dominance prevented any hope of rescue . They could remain at Wewak , move west to try and link up with another Japanese force , or surrender . Surrender was not an option . Staying in place meant starvation as supplies whittled away . So , the Japanese army commander , General Hatazo Adachi , decided to take approximately thirty-five thousand men west . Their ultimate objective : Aitape and Hollandia . To get there , they had to cross the nearby Driniumor River . Only fifteen thousand of that force ever reached the vicinity of the Driniumor , the jungle savaging their ranks , and only five thousand were combat troops . ULTRA told General Krueger all of this . 25
The Japanese were expected to reach the Driniumor in early July . At that time , in addition to garrisoning Aitape and Hollandia , Sixth Army units were conducting operations further west at Sarmi and Biak and other operations were imminent . Suddenly , a substantial enemy force could appear in Sixth Army ’ s rear , threatening everything else . Krueger received two vital ULTRA messages in late June . The first quoted General Adachi , stating : “ we are staking all on an encounter with the enemy in the vicinity of Aitape about 10 July . At present we are preparing to attack .” 26 The second was very specific as to troop and equipment strength , intentions , and dispositions .
The attack planned against Aitape is scheduled to begin about 10 July and to be made by approximately 20,000 troops ... the 20th and 41st Divisions are to participate in the attack and enumerates the following additional troops to be attached to the 41st Division : the 66th Infantry Regiment of the 51st Division , 1 mortar company , and a provisional Army artillery unit composed of Army and Navy Anti-Aircraft troops .... The 20th Division is believed to be located on the right bank of the Driniumor River ( about 20 miles east of Aitape ). The 41st Division and the attached troops are scheduled to be concentrated in the Yakamul-Ulau area about 5 July . The plan calls for the 20th Division to attack west across the Driniumor River , while the 41st Division moves around to the south and attacks north and northwest towards the Aitape and Tadji airfields . The 18th Army has made a number of urgent requests for submarine shipment of materials ( principally wire-cutters and signal equipment ) necessary for the Aitape operation . An indication that it has been having serious local supply difficulties as well appears
185