19th Infantry Regiment on Route 1 moving through hemp plantation toward Davao.
The Japanese had long expected MacArthur to begin his reconquest of the Philippines with an invasion of eastern Mindanao. Believing that the American attack would come in the Davao Gulf area, they had built their defenses accordingly. Greatest attention had been paid to defenses around Davao City, the island’s largest and most important city. Strong coastal defenses stretched along the shoreline, which bristled with artillery and antiaircraft batteries. Davao Gulf itself was heavily mined to counter an amphibious landing. Inland, the Japanese had prepared defenses in depth, in keeping with their intention of prolonging the campaign as much as possible. Anticipating that they ultimately would be driven from Davao, the Japanese also prepared defensive bunkers in the jungle behind Davao to which they could retire. Situated from two to four miles inland, the extensive fortified positions ran from approximately thirteen miles southwest of Davao City to about twelve miles north of the city.
There were 43,000 Japanese troops on Mindanao under the command of Lt. Gen. Gyosaku Morozumi. The 100th Infantry Division and the 32d Naval Base Force were concentrated around the prepared defenses north of Davao. The 74th Infantry Regiment and the 2d Air Division were at Malaybalay in the center of the island. The 30th Infantry Division held the area between Malaybalay and Cagayan in the central region and northern coast. Finally, and as noted earlier, the 54th Independent Mixed Brigade remained on the Zamboanga Peninsula.
On paper the Japanese forces seemed formidable. But numerous supply shortages-artillery and ammunition, communications equipment, and transportation vehicles-left the defenders unable to compete with the Americans at the operational level. Further complicating life for the Japanese was a vibrant guerrilla force led by Col. Wendell W. Fertig, an American reservist who had escaped from Bataan in 1942. By mid-April 1945, Colonel Fertig’s 24,000-man force controlled most of the island, keeping the Japanese confined to their garrison towns and to the major roads. The guerrillas were prepared to participate actively in future actions. Also working against the Japanese was their belief that the March 1945 operations in the Zamboanga Peninsula by General Doe’s 41st Division constituted the extent of American plans for Mindanao.
On 11 March General MacArthur formally ordered the Eighth Army to clear the rest of Mindanao in Operation VICTOR V. MacArthur expected that the campaign could take four months. Eichelberger thought otherwise. Based on his knowledge of how the Japanese units were disposed, he expected the strongest Japanese resistance to be centered around Davao City, in eastern Mindanao. In just over two weeks of hard work, Eichelberger’s Eighth Army staff produced an operation plan to deal with the Japanese dispositions as efficiently as possible. Instead of the expected frontal assault into the teeth of the Japanese defenses, the plan called for securing a beachhead at Illana Bay in the undefended west, then a drive eastward more than one hundred miles through jungle and mountains to strike the Japanese from the rear. If the invading force achieved surprise and pressed forward quickly and aggressively, Eichelberger calculated, the attack would unhinge the Japanese both physically and psychologically. The plan was not without risk. Success was highly dependent on the beachhead performance of the landing force at Illana Bay and then on the ability of the Americans to maintain the momentum of their attack. The invading force had to move faster than the Japanese could react and had to do so before the rainy season arrived and turned every island road and trail into a morass.
Eichelberger assigned ground operations to Maj. Gen. Franklin C. Sibert’s X Corps. Sibert’s principal combat units were the 24th Infantry Division, under Maj. Gen. Roscoe B. Woodruff, and the 31st Infantry Division led by Maj. Gen. Clarence A. Martin. The plan called for Task Group 78.2, now under Rear Adm. Albert G. Noble, to carry the 24th Division and the X Corps headquarters to the assault beaches near Malabang on 17 April to secure an advance airfield. Then, five days later the 31st Division would be transported twenty miles farther south to Parang, located near Highway 1, the route to Davao.
As Task Group 78.2 moved toward Illana Bay, Colonel Fertig sent welcome word that his guerrillas owned Malabang and its airstrip. Earlier, Fertig’s men had trapped a battalion-size force of Japanese within Malabang, but could not evict them. Beginning on 3 April, Colonel Jerome’s Marine aviators from Dipolog landed at the airstrip, received targeting information from the guerrillas, and then bombed the Japanese positions. This broke the stalemate, and by 14 April the surviving Japanese had fled through the guerrilla lines.
With friendly forces in complete control of Malabang, an opportunity was presented to speed the initial penetration of central Mindanao. Generals Sibert and Woodruff and Admiral Noble quickly changed their plans to take advantage of the new developments. Although one battalion from the 21st Infantry would still land at Malabang, the bulk of the 24th Division was to come ashore at Parang, much closer to Highway No. 1, and thus speed up the entire operation.
The landing at Parang on 17 April went unopposed, and the division quickly headed inland along Highway 1. Correctly perceiving that the Japanese would destroy the bridges along the highway, the planners decided to use the 533d Engineer Boat and Shore Regiment, 3d Engineer Special Brigade, to exploit the Mindanao River. This waterway ran roughly parallel to Highway 1 and was navigable for thirty-five miles, some ten miles west of the crucial town of Kabacan and the north-south Sayre Highway. On 21 April Lt. Col. Robert Amory led a small fleet of gunboats upriver and seized Kabacan and the junction of Highway 1 and the Sayre Highway the next day. The Japanese garrisons, startled by the sudden appearance of an American freshwater navy, fled north and west. The Mindanao River soon became the main line of supply as troops and supplies were offloaded far upriver. If “not for the successful completion of this river campaign,” Admiral Noble stated, “our forces would be at least a month behind their present schedule.”
General Martin’s 31st Division began landing on 22 April, the same day that Marine Air Group 24 arrived at Malabang to provide air support for Mindanao ground operations. With both divisions ashore and ahead of schedule, Sibert ordered them to undertake separate thrusts. General Woodruff ‘s 24th Division, minus the 21st Infantry in corps reserve, was to continue its advance along Highway 1 to Digos, then seize Davao City. General Martin’s 31st Division would follow to Kabacan and then attack north up the Sayre Highway toward Macajalar Bay.
In hindsight, the Japanese erred in allowing the Americans to seize the key road junction of Kabacan so easily. Not only did X Corps build momentum and develop its lines of supply uncontested, but the American advance split the 30th and 100th Divisions. General Morozumi’s two main divisions became hopelessly separated, with the 30th in central and northern Mindanao and the 100th near Davao. Both divisions now were vulnerable to destruction in detail by Sibert’s X Corps. The Japanese “error,” however, was the direct result of the surprise achieved by Eichelberger’s decision to land at Illana Bay-surprise that the X Corps subsequently exploited and capitalized on with its rapid advance from the beachhead.
General Woodruff ‘s 24th Division moved so rapidly that his troops were almost on top of the Japanese around Davao before Morozumi learned that the western landing was, in fact, not a feint. Reaching Digos on the Davao Gulf on 27 April, the Americans quickly overwhelmed the Japanese defenders who were prepared only to repel a seaward assault-not an attack from their rear. The division then turned north and headed toward Davao City. On 3 May, its combat elements entered Davao City against less opposition than had been expected. The Japanese had contented themselves with destroying the city as best they could before withdrawing inland.
In just fifteen days, despite severe heat and humidity and near-constant rain, Woodruff ‘s two regiments had traveled 115 miles and seized the last major Philippine city under Japanese control. Eichelberger’s plan had succeeded. MacArthur was enthusiastic, and he paid Eichelberger what probably was his greatest compliment: “You run an Army in combat just like I would like to have done it.” That same day MacArthur announced that “strategic victory had been achieved on Mindanao.”
Up to this point General Woodruff had bypassed the main defenses of the 100th Division. Now, he turned to eliminate them. The battle lasted into June. The “soldiers of his outfit,” wrote a chronicler of the travails of the 24th Division, considered the post-Davao operations to be “the hardest, bitterest, most exhausting battle of their ten island campaigns” against the Japanese. In addition to the tenacious Japanese defense, another punishing aspect of the subsequent combat was the proliferous fields of abaca. As the same 24th Division reporter recalled:
To the foot soldiers fighting in the Davao province, the word abaca was synonymous with hell. . . . Countless acres around Davao are covered with these thick-stemmed plants, fifteen to twenty feet high; the plants grow as closely together as sugar cane, and their long, lush, green leaves are interwoven in a welter of green so dense that a strong man must fight with the whole weight of his body for each foot of progress. . . . In the abaca fields visibility was rarely more than ten feet. No breeze ever reached through the gloomy expanse of green, and more men-American and Japanese-fell prostrate from the overpowering heat than from bullets. The common way for scouts to locate an enemy position in abaca fighting was to advance until they received machinegun fire at a range of three to five yards.
In such an environment, the 24th Division fought the Japanese for the next two months. It now did so at full strength. Recognizing the need to bolster his line troops, General Sibert had obtained the release of the 41st Division’s 162d Regimental Combat Team from reserve on Zamboanga. Sibert sent one battalion to protect the 24th Division’s immediate rear and assigned the rest of the regiment responsibility for the area from Illana Bay to Kabacan, thus allowing the 21st Infantry to return to General Woodruff.
As Woodruff ‘s infantry assaulted the Japanese defenses, platoons and squads cautiously worked through the abaca and surrounding jungle seeking out Japanese bunkers and spider holes. On the left flank, the 21st Infantry encountered intense resistance clearing the Libby Airdrome and the village of Mintal, some five miles west of Davao City. Pushing headlong into the Japanese defenses, the regiment was assailed from three sides by a numerically stronger enemy. Individual acts of heroism often spelled the difference between victory and defeat in the desperate fighting. Pfc. James Diamond of Company D was one of many who performed acts of great courage-killing enemy attackers, volunteering to repair a bridge that was under Japanese fire, creeping close to Japanese positions to direct fire, and volunteering to evacuate wounded soldiers while under fire. On 14 May he was leading a patrol to evacuate more casualties when his small force came under heavy attack. Disregarding his personal safety, Diamond sprinted to an abandoned machine gun, drawing enemy fire and allowing the rest of the patrol to reach safety. Wounded, he died while being rushed to an aid station and was posthumously awarded the Medal of Honor.
Combat was just as severe along the rest of the 24th Division front. The 34th Infantry tried to make headway in the center as it moved up the Talomo River and into the middle of the 100th Division, while the 19th Infantry consolidated its hold around Davao City and probed north along the coast. Progress was slow.
On 17 May the 24th Division renewed its offensive. The 21st and 34th regiments attacked in the west, while the 19th Infantry prepared to swing around the Japanese eastern flank and join up with a division of Fertig’s guerrillas. As before, the fire of Japanese artillery, mortars, rockets, machine guns, and small arms made the advance slow and costly, but the infantry crept forward behind the steady pounding of artillery and Marine close air support. In such fashion, and reinforced by the 3d Battalion, 163d Infantry, the two regiments chewed through the main Japanese defenses, inflicting heavy casualties on the defenders. Beginning on 29 May, the 19th Infantry and Filipino guerrillas caved in the Japanese eastern flank, seizing the town of Mandong on 15 June and the eastern bank of the Davao River, which flows from north to south into Davao City. By now, the defenses of the 100th Division had collapsed, and the sorely weakened unit was in retreat. To this point, the 24th Division had lost 350 men killed and 1,615 wounded; the Japanese had lost approximately 4,500 killed.
The surviving Japanese moved back toward the mountains to the north, making stands of varying intensity, as the Americans pursued and began the usual and deadly process of mopping up bypassed pockets. During these actions, Col. Thomas “Jock” Clifford, the commander of the 19th Infantry, was killed by mortar rounds fired by bypassed Japanese. Colonel Clifford, whom both Sibert and Eichelberger described as one of the best combat leaders they had known, was a veteran of New Guinea and Leyte. Although mopping up operations continued to claim American lives, the relentless 24th Division pursuit destroyed the 100th Division’s cohesion, forcing it to abandon its last efforts at organized defense in mid-July. Breaking into small groups, the Japanese soldiers dispersed into the mountains, followed by Filipino guerrillas.