substituted. In view of the difficulties involved in changing plans, and moving the troops around, MacArthur agreed to postpone both operations, Wakde until 17 May and Biak to 27 May. As a result, Alamo Force became involved in desperate fighting on three different fronts simultaneously. The landing at Wakde was opposed by nearly twice as many Japanese troops than had been expected. When Krueger discovered that the Japanese were massing for an assault on the American position, he ordered a pre-emptive attack. "Krueger", wrote Edward Drea, "was too good a soldier to stand pat and wait for a Japanese attack." Official historian Robert Ross Smith noted that "This decision, based upon the scanty, incomplete information concerning Japanese strength and dispositions available to General Krueger at the time, was destined to precipitate a protracted and bitter fight." However, even if Krueger had known the true size of the Japanese force, he might still, under the circumstances, have taken the same approach. The estimates of the number of Japanese troops on Biak were out by a similar margin, resulting in heavy casualties. In the Battle of Biak, stubborn Japanese resistance halted the 41st Infantry Division, and forced its commander, Major General Horace H. Fuller, to appeal to Krueger for reinforcements. In response, Krueger sent the 163rd Regimental Combat Team from Wakde. MacArthur soon grew impatient, as he needed the airstrips on Biak to support Admiral Chester Nimitz's Invasion of Saipan. Nimitz's operation ultimately drew Japanese attention away from Biak. MacArthur put pressure on Krueger for results, and Krueger in turn put pressure on Fuller. Krueger decided that Fuller had too many responsibilities as both task force commander and division commander, and decided to supersede him by sending Eichelberger to take over the task force. Fuller then submitted his resignation. Eichelberger's chief of staff, Brigadier General Clovis Byers, offered to have Decker intercept and destroy the resignation before Krueger saw it, but Fuller decided against this. The battle raged for nearly a month. Afterwards, Krueger demanded an explanation from Eichelberger as to why he had allowed Fuller to quit. Meanwhile, Japanese forces under Lieutenant General Hatazō Adachi attacked Alamo Force's position at Aitape in the Battle of Driniumor River. Krueger called for an energetic defense, but the cautious commander of XI Corps, Major General Charles P. Hall, retained nine battalions around the airbase at Tadji. This left Brigadier General Clarence A. Martin without