Joint Force Quarterly 113  –  

Download PDF

As Alfred Thayer Mahan stated, “The study of history lies at the foundation of all sound military conclusions and practice.”¹ When we consider maritime strategy today, analysis of the Pacific War offers substantial lessons. For centuries, the Pacific has proved crucial to the global economy and as a stage for Great Power competition. In the late 19th century, European powers vied for control over rubber, oil, and minerals, as well as external markets for their domestically produced consumer goods. Mimicking the foreign policy of other imperial nations, Japan sought to revise the European-dominated regional order to better serve its own national interests. The Japanese Imperial Army began conquests in China in the 1930s and then—after Japan proposed the Greater East Asia Co-Prosperity Sphere in 1940—set its sights on Southeast Asia in the 1940s. Sea lines of communication between the Japanese home islands and their territorial expansions became imperative. In the geographic center of this ambitious Japanese strategy lay the U.S.-controlled Philippine Islands.

The competing interests of two great Pacific powers—Imperial Japan and the United States—resulted in the largest naval conflict in world history. While Americans often focus on the climactic battles at sea, control over the Philippine Islands remains of equal importance to those naval battles. In the struggle over the Philippines, seapower provided the most decisive means of maintaining military dominance, but unconventional warfare afforded an asymmetric approach to contest it.

The U.S. Achilles’ Heel

Nearly as soon as the United States defeated Spain in 1898, and then after its subsequent war with the First Philippine Republic from 1899 to 1902, the U.S. Army and Navy initiated plans on how to properly defend America’s new Philippine territory. The wars for control over the Philippines had exposed a U.S. Achilles’ heel.² The United States had always relied on its geographic isolation in North America as an imposing fortress. Now, millions of noncitizen U.S. nationals lay outside those boundaries and within the periphery of many European-controlled Pacific territories.³ Retaining U.S. dominion of its new imperial estate resulted in direct competition with these other Great Powers.

American concerns dramatically increased with the rise of Imperial Japan. In 1905, Japan defeated Russia in the Russo-Japanese War—a shocking result that included the utter destruction of the Imperial Russian Navy. Of great concern, the Japanese home islands lay much closer to the Philippines than did the continental United States. Consequently, military planners needed to understand how America would defend the islands against a technologically sophisticated and ideologically inspired near-peer competitor.

In 1903, the United States organized the Joint Army-Navy Board, a panel of eight members who reviewed and coordinated strategy. The Board organized a series of schemes concerning how to defend the United States against other Great Powers. To identify each potential adversary, the plans evolved into colors. Orange was the color selected for Japan, and consequently War Plan Orange emerged. From this point onward until the Japanese attack on the Philippines 30 years later, the Army and Navy conducted many wargames and revised a series of Orange plans for a potential conflict.

Each generation of U.S. officers perceived the Philippines in terms of the same Achilles’ heel. In the advent of war, the Navy would not be able to secure the sea lines of communication with the Philippines for many months. This meant that any Army forces defending the islands would be stranded. For decades, military planners revisited a series of Orange plans with the same dilemma. The optimistic compromise, which no one felt enthused about, was that the Army could hold out for some amount of time until the Navy could consolidate enough forces from both the Atlantic and the Pacific. Then this combined force would have the requisite mass for a climactic battle with the Imperial Japanese Navy and subsequently save the garrison in the Philippines.⁴

Remarkably, military planners understood the challenges of defending the Pacific from the aggression of a modern Asian power decades in advance and still failed to adequately address the flaws in their underlying strategy. Most planners understood that with the loss of sea control, conventional defense of the Philippines would remain uncertain at best and doomed at worst. At the same time, the Army’s mission included defense of U.S. territory—a duty that it could not discard. Instead, the defense mission (seemingly a lost cause) was simply neglected. This situation of ignoring the problem began to change under the leadership of Philippine President Manuel Quezon in 1935.

A Conventional Defense of Thousands of Islands

The Philippines had sought the goal of independence for many decades. In its current form of governance, thousands of islands and dozens of multi-ethnolinguistic peoples were represented in a commonwealth system— all under the supervision of the U.S. Congress. However, the United States had promised that the subservient condition of the Philippines was only temporary and that Philippine independence was the goal (although the United States planned to retain military basing rights). Consequently, prior to hostilities, the Philippines had negotiated a full path toward independence. However, with the impending war between Japan and the United States, achieving liberation while maintaining neutrality appeared unachievable.

Quezon realized that the vital strategic locations of the Philippine Islands generated imminent danger from Great Power competition. Simply put, the forthcoming conflict between two superpowers would not allow Filipinos to act as bystanders. With a good sense of the inevitable, Quezon made a choice: to defend the Philippines from Japanese invasion, even though those actions would bring his nation directly into war. With great calculation, Quezon sought out the most qualified military general to assist with this task: a war hero and Chief of Staff of the U.S. Army, Douglas MacArthur.⁵

Accustomed to War Plan Orange and its gloomy strategic outcomes, MacArthur promised Quezon that the islands could be defended and the improbable achieved.⁶ He retired from the Army in 1937 and fully committed himself to Quezon’s task, moving to Manila as Military Advisor to the Philippine Commonwealth. MacArthur recommended and implemented a Philippine conscription system to build a national army—one trained and supervised by U.S. Soldiers. This idea had its skeptics, including many from within the U.S. military.

Although shortfalls certainly hampered the development of the Philippine army, the primary problem was an incongruence between the diverse cultures of the Filipino tribes and the unifying components of national identity required to amalgamate a conventional force. One U.S. officer explained: “[I]n most Philippine army units many men could not understand the languages of most of the others; moreover, they had been together so briefly that they had not had time to learn one another’s names, much less develop mutual confidence or collective esprit de corps.”₇ Then there were the materiel issues:

More than a few units had first sergeants and company clerks who could not read or write. Vehicles of every type were notable mainly by their absence, and the available rifles were mostly ancient British Enfield’s [sic], in some of which the steel extractors had deteriorated so badly in tropical heat and humidity that they broke when used. The only ammunition for these relics dated from 1914 or before.⁸

The situation at sea appeared equally discouraging. During a period of intense technological advancement, naval power in the Pacific had dramatically changed in the two decades between the 1920s through the 1940s. While not capable of competing with the scale of the U.S. Navy, Imperial Japan developed the most sophisticated and technologically advanced navy in the world. Arguably, Japan was first to fully realize the primacy of the aircraft carrier. By 1941 it had built 10 carriers and greatly improved carrier operations by flying combat missions off the coast of China in support of the Imperial Army. Many Japanese veteran pilots now operated the Mitsubishi A6M “Zeke” (commonly referred to as the Zero), with a reputation as the most agile fighter while at the same time demonstrating incredible range. Hedging their bets on the future of naval warfare, the Japanese simultaneously built the largest battleships in history, with enormous 18-inch guns. In another attempt at achieving naval superiority, the Japanese developed unmatched night combat procedures with complementary arrangements for cruiser and destroyer torpedo attack—torpedoes that boasted much longer ranges and higher explosive yields than their American counterparts. The Imperial Navy deliberately designed all these impressive leaps in naval technology and tactics to offset size disadvantages with the U.S. Navy.⁹

The imposing seapower developed by Japan over two decades facilitated its invasion of Luzon and the other major Philippine Islands in December 1941, leading to one of the most humiliating American defeats in history. In mid-1941, the United States finally committed additional resources for a conventional defense of the islands but without the same sea and air forces needed to maintain sea control. Fresh submarines, fighters, and bombers remained too few, while the Asiatic Fleet was generally composed of antiquated surface ships. Adequate defense under these conditions proved unattainable. The newly formed Philippine army’s performance against the Imperial Army was predictable in terms of its mediocrity. Surprisingly, however, it remained steadfastly loyal to MacArthur and attempted to follow every order from his United States Army Forces in the Far East. The disastrous defeat of the U.S. Navy’s Pacific Fleet at Pearl Harbor by the Japanese First Air Fleet further compounded any chances of a relief force. Meanwhile, Imperial Japan undertook steps to secure an impressive naval defense perimeter in the Central Pacific (locations between Hawaii and the Philippines). In the Mariana Islands, Caroline Islands, Gilbert Islands, and Marshall Islands the Japanese built naval bases, airfields, and fortifications. Philippine defenders soon realized that support from the United States would not be forthcoming for years.

With the end of America’s defense efforts in sight, MacArthur escaped Luzon on March 11, 1942. While in Mindanao and en route to Australia, MacArthur convinced President Quezon (who was on Panay in the central Visayan Islands) to depart with him. While trapped on Corregidor during the initial Japanese invasion, Quezon had seriously considered returning to Manila and preserving his administration under Japanese occupation.¹⁰ Instead, the U.S. evacuation of Quezon led to the establishment of a Philippine government-in-exile in Washington. Quezon’s departure preserved a highly public and internationally recognized Philippine authority, one that continuously delegitimized Japan’s attempts to create a credible puppet state. General Jonathan Wainwright surrendered his defenders on Corregidor and the rest of the Philippines on April 9, 1942. In the largest defeat in U.S. history, the Japanese “had driven the United States from its stronghold in the Far East, destroyed a combined American and Philippine Army of 140,000 men, and forced the Far East Air Force and the Asiatic Fleet back to the line of the Malay Barrier.”¹¹

Philippine Resistance to Japanese Occupation

Perhaps a surprise for those unfamiliar with Philippine history, the disastrous end to conventional defense of the islands failed to stifle local opposition to occupation. In their past, Filipinos had lost many conventional battles for independence, from Rajah Sulayman’s surrender of Manila to the Spanish in 1570, to General Emilio Aguinaldo’s surrender to the Spanish in 1897, and to General Miguel Malvar’s surrender to the United States in 1902. These types of reverses only reinforced the accepted forms of irregular warfare practiced by Filipino tribes for centuries—methods of resistance at which they were particularly good. Many of the men and some portion of equipment from the defeated Philippine army soon became integrated within the armed factions of the Tagalog, Cebuano, Ilocano, Bicolano, Kapampangan, Maranao, and many other peoples.

In 1942, while MacArthur reestablished his headquarters in Australia (eventually called the Southwest Pacific Area command, or SWPA), he became aware of the outbreak of dozens of Philippine resistance movements. In southern Luzon, a Tagalog resistance— President Quezon’s Own Guerrillas—formed. In central Luzon, the Tagalog and Kapampangan supported the communist Hukbalahap movement. Also in Central Luzon, the Tagalog, Ilocano, Pangasinan, and Kapampangan supported Luzon Guerrilla Army Forces. In eastern Luzon, the Tagalog supported the East Central Luzon Guerrilla Forces. In northern Luzon, the Ilocano and Igorot supported U.S. Army Forces in the Philippines–Northern Luzon. In the central Philippine Islands, the Hiligaynon, Hamtikanon, Capiznon, and Akeanon formed the Free Panay Guerrilla Forces. In the southern Mindanao islands, the Maranao, Bisaya, and Cebuano formed the Maranao Militia Force. These impressive resistance movements represented only a few of the major organizations, with many smaller ones spread throughout (map 1).¹²

Map 1. Major Guerrilla Forces in the Philippines, 1942–1945

Unconventional Warfare and Support to Resistance

With little hope of direct military action in the Philippines as the United States built up its forces through 1942 and early 1943, MacArthur began to realize the potential of irregular warfare in the Philippines. Imperial Japan struggled with the same challenges previous occupiers had. While the Imperial Army maintained a firm grip in Manila, it lacked the forces for complete subjugation of 2,000 inhabited islands. In fact, most of these islands had never been under firm control of an external power. Left unmolested, Filipinos may have stayed clear of the fighting, but now Japan and the United States vied for their loyalties, and many chose one side or the other. Fittingly, MacArthur (from 6,000 kilometers away in Melbourne) started to see the value of influencing disparate populations in opposition to Japanese occupation. Fortunately, the indigenous residents needed little encouragement to resist invaders, which they had done for centuries. Regarding the newly discovered opportunities for unconventional warfare, SWPA’s lines of effort included establishing communications, leveraging influence operations, exploiting indigenous intelligence networks, and supplying arms and equipment to resistance forces.

Communications

Initially, SWPA had no communications with the resistance movements, a situation resolved primarily by Filipinos. According to one U.S. report, “the Federal Communications Commission monitoring station at San Leandro, California, intercepted an unidentified radio station with the callsign VCJC attempting to contact General Douglas MacArthur’s Southwest Pacific Area Headquarters” in June of 1942.¹³ It remains unclear which resistance movement used the callsign VCJC at the time, but the organization apparently functioned in the Luzon islands. SWPA initially discounted this transmission as stemming from the Japanese army, but such transmissions would intensify.

Probably the most prominent and largest organization to establish communications with SWPA was the Free Panay Guerrilla Forces (FPGF), under the leadership of Macario Peralta, Jr., who contacted SWPA as early as November 1942.¹⁴ From that point onward, many guerrilla organizations desiring contact with MacArthur relayed information through the “bamboo telegraph” to Peralta, who distributed them to SWPA. Once Philippine guerrillas discovered effective radio capabilities, each group sought to establish its own means as quickly as possible.

American Wendell Fertig, appointed leader of the Maranao Militia Force on Mindanao, was one of the next outfits to establish communications with SWPA, in February 1943. Three Filipinos— Gerardo Almendras, Eleno Almendras, and Florentino Opendo—constructed a transmitter.¹⁵ Fertig then instituted a round-the-clock unit called Force Radio Station to carry out radio traffic. Due to its reliability and frequency of communiqués, Force Radio Station became one of the most important resistance communication nodes. The Maranao Militia Force’s more secure position in the southern islands allowed it not only to transmit its own messages but also to relay the messages of other resistance movements, all relatively free of raids from Japanese ground forces.¹⁶ Essentially, Force Radio Station was a “24 hour a day, seven days a week operation.”¹⁷ Substantial radio networks established in the Visayas and Mindanao by late 1943 are indicated on map 2.

Map 2. Allied Radio Network in December 1943

General Vicente Lim’s underground movement in Manila put together its radio from stolen components of Japanese military radio transmitters—an effort that cost his underground organization many lives.18 Once their radios were constructed, Lim’s movement and other movements on Luzon had challenges, one of which included the need to frequently change locations when the Japanese triangulated the positions of their transmissions. The other challenge, particularly for guerrillas in remote locations, involved finding sources of electricity. One ingenious method used by the FPGF was to power batteries with improvised stationary bicycles.¹⁹

One of the most enterprising aspects of numerous guerrilla outfits was their ability to intercept and decrypt Japanese messages before sending them forward to SWPA. The radio operators likely listened in to the Philippine puppet government’s inter-island, high-frequency radio system. The communiqués intercepted included assessments by high-ranking government officials. Somehow, guerrillas also captured Japanese communications with essential information such as troop movements and unit status reports.²⁰

The number of resistance radio stations operating inside the denied area of the Japanese army was incredible. On the island of Panay alone, the FPGF operated 18 radio stations.²¹ One U.S. after-action report summarized that the guerrillas employed 120 radio stations in total on the islands.²² Additionally, the U.S. Army—primarily via submarine— eventually “supplied radios, technical personnel, codes, ciphers, signals operating instructions and even M-94 and M-209 cipher devices for the guerrillas to use.”²³ Providing codes and ciphers to Philippine rebels demonstrated a great degree of trust from SWPA, as these items could prove dangerous if captured by the Japanese. Meanwhile, Philippine resistance movements provided an extraordinary amount of vital intelligence, which included Japanese troop locations, details of military installations, navy and aircraft movements, the morale of enemy and friendly forces, the status of prisoners of war, and the names of Japanese collaborators.²⁴

Psychological Warfare

Along its second line of effort, SWPA eventually produced an information campaign. MacArthur’s propaganda effort became quite famous, highlighted by the well-known phrase printed on multiple mediums: “I shall return.” However, SWPA neglected the potential for information operations for quite some time, and its efforts generally excluded attempts to win the loyalties of local populations.²⁵ In fact, not until June 1944 did MacArthur establish his Psychological Warfare Branch. The late timing of this organization indicates that information warfare activities generally supported MacArthur’s upcoming invasion but not particularly the ongoing resistance to occupation.

Once established, the Psychological Warfare Branch aimed to demoralize the Imperial Army and hasten the collapse of any pro-Japanese governance.²⁶ Accordingly, many leaflets dropped on the Philippines in 1944 were written in Japanese and intended for the occupying forces. Despite any perceived deficiencies in SWPA’s information campaign, one scholar describes it as “the most intensive effort to weaponize cultural knowledge and penetrate enemy psychology for strategic ends.”²⁷ Another interesting decision by SWPA that influenced its approach to information operations was to keep the presence of guerrilla activities a secret. Consequently, the American public did not learn of Philippine guerrillas until after the invasion. This decision about concealing the presence of resistance derived from the desire to protect the identities of participating U.S. Servicemembers. However, not publicizing the pervasive Filipino movements might be considered a lost opportunity.

In contrast to the Psychological Warfare Branch, Philippine undergrounds began information campaigns to win hearts and minds of local populations almost immediately following American defeat. President Quezon’s Own Guerrillas established the Manila Free Press as one such printed source of advertising resistance, and likely the most influential example. Illustrations of clandestine radio broadcasts included “Voice of Freedom” and “Voice of Juan de la Cruz.”²⁸ In 1942, the Japanese discovered and executed many local resistance radio broadcasters. Consequently, the San Francisco radio station KGEI became the most popular Allied news source; Filipinos could receive it via shortwave radio (although the Japanese deemed doing so a crime). Exiled Filipina broadcaster Carmen Ligaya’s daily program “Music America Sings” proved very popular. For those without access to radios, the underground often distributed news via leaflets (typed on recycled paper). At the local levels, resistance propaganda—whether by print, radio, or word of mouth—was pervasive.

Intelligence

Along its third line of effort, SWPA realized the potential for exploiting indigenous intelligence networks. Following defeat, MacArthur’s headquarters in Australia lost nearly all situational awareness of activities in the Philippines. Radio contact with the FPGF was the first indication that underground networks existed and could be used as an entry point for intelligence. William Donovan, from the newly created Office of Strategic Services, attempted to create a spy network in Manila.²⁹ However, MacArthur refused any interference within his region, instead desiring to construct his own intelligence services. In October 1942, Allied Intelligence Bureau (made up of American, British, Dutch, and Australian counterparts) established a separate Philippine division specifically for developing information “on the military, political, and economic aspects of the Japanese-dominated Philippine Government, as well as on the attitudes of the guerrillas themselves.”³⁰

While submarines served as a vital clandestine means of transportation, Allied Intelligence Bureau used other means as well, particularly commercial vessels such as fishing boats. In December 1942, the Allied Intelligence Bureau inserted five Filipino agents back into the islands. In a simultaneous effort, the Maranao Militia Force sent three guerrillas to Australia in a small boat.³¹ From this point forward, the movement of spies back and forth from the Philippines to Australia became somewhat routine. Even President Quezon leveraged this network to send to the islands his own operative, Dr. Emigdio C. Cruz, with orders to contact influential resistance leadership. Cruz was inserted via the submarine USS Thresher from Australia to Negros Occidental in July 1943; he was eventually extracted and made his report to Quezon in Washington, DC.³² While setbacks occurred, once these networks solidified, indigenous intelligence provided SWPA essential information on strategic, operational, and tactical aspects.

Map 3 illustrates the infiltration of multiple agents, landing at will throughout the Philippine Islands. These missions illustrate two important facts: (1) the clandestine use of submarines and commercial vessels for insertion and extraction of agents into a denied area was a highly successful method, and (2) the extensive and pervasive resistance undergrounds allowed for excellent penetration and access. Intelligence agents using submarines included Chick Parsons, Jesus Villamor, Charles Smith, Jordan Hamner, Emigdio C. Cruz, Jay D. Vanderpool, George Rowe, and many others. Map 3 does not highlight the totality of intelligence agent insertions, but it provides a solid snapshot.

One key member of the resistance who constantly supported SWPA intelligence included the previously mentioned Vicente Lim. Lim’s frequent hospital stays helped him remain free of impressment into the Philippine Constabulary. As such, it is difficult to ascertain which of his ailments were real or imagined. Lim’s underground network consisted primarily of Philippine army officers such as Amado Bautista, Tomas Domaoal, Amado Magtoto, and Alfredo Santos. But his network also included frequent communications with the Philippine government, including Senators José Ozámiz and Manuel Roxas. While Lim avoided service in the Philippine puppet regime, he encouraged others to serve and act as double agents. Until his imprisonment and execution, Lim “conducted intelligence work, gathered information through trusted officers and individuals, and continued formulating plans.”³³ Lim’s ambition was to unite all the Philippine guerrilla movements under one command (presumably with himself in charge). Despite Lim’s attempt not to expose his activities, his high-profile position made it easy to identify him as a member of the resistance. Lim was quite aware of this fact and tried to escape Manila for Australia. The Japanese arrested General Lim in 1944 and executed him.

Another important Philippine operative was Josefina Guerrero, who had leprosy. Guerrero was a solid intelligence agent, and her disability assisted in her movements and activities. Visible lesions on her face and exposed arms ensured the Japanese left her movements uninterrupted and unsuspected.³⁴ Following the Japanese invasion, Guerrero persistently sought out the Manila underground and volunteered her services as a spy. Once she was finally accepted, she used her condition to gain quick access and move unmolested through searches at checkpoints. As a courier, she typically relayed written messages by placing them in her hair bun. She also acted as a courier of weapons and supplies. Another important task for Guerrero included walking around the city and mapping out Japanese defenses.³⁵

^{Map 3. Intelligence Agent Insertions Into the Philippines, 1943-1944}

One of Guerrero’s most dangerous and important missions came when the underground asked her to provide a detailed map to the U.S. Army in January 1945. The underground had identified the locations of Japanese mines laid on routes of advance toward Manila. If this information were in the hands of the Americans, U.S. Soldiers might avoid these dangerous impediments. Guerrero taped the map on her back, between her shoulder blades. With absolutely no knowledge of the American positions, she departed on a 35-mile trek through multiple Japanese checkpoints. Exhausted by her illness but relentless, she navigated her way through dangerous combat conditions to finally meet up with the U.S. Army’s 37th Division at Calumpit, Bulacan. Not only did Guerrero provide the important map, which likely saved many American lives, but she also provided a host of other important intelligence, including vital information on the Santo Tomas Internment Camp, in Manila.³⁶

By the time the 6th and 8th Armies landed in late 1944, SWPA and Allied Intelligence Bureau had established extremely accurate information on Japanese army locations and activities, which proved a critical factor for planning the invasion. As one example, an intelligence report dated May 31, 1944, regarding Nueva Vizcaya Province on Luzon, detailed the number of Japanese troops at 14 locations as well as the numbers of the Philippine Constabulary. Reports also provided information on unit morale, training, and activities.³⁷ Incredibly, intelligence reports often detailed the names of each Japanese commander and a description of the units they commanded. Additionally, reports provided comprehensive information on U.S. prisoners of war, and there was great demand for this.³⁸ The amount of detail provided by intelligence efforts in the Philippines is staggering and perhaps the most comprehensive in the history of modern warfare. Such intelligence efforts continued to support the U.S. Army’s reoccupation of the Philippine Islands until the end of the war, all of which was made possible by underground resistance.

Submarine Operations

At times these techniques used commercial craft, but the most significant form derived from adaption of conventional submarines. Operations began in January 1943, landing supplies on the Negros Islands in the Visayas. The quantities of materials a submarine could deliver (normally 1 or 2 tons) proved remarkable, particularly for the nominal needs of resistance movements that had no other readily available sources of sustainment.

From the earliest stages of war in the Philippines, submarines had conducted a special mission for personnel transport and resupply. Submarines supported the United States Army Forces in the Far East during the defense of Bataan Peninsula. Submarines made possible the movement of the Philippine national treasury (in gold bars) from Manila to their eventual destination in the United States. And, once MacArthur established SWPA in Australia, submarines continued to conduct clandestine missions to the Philippine Islands.

Over time, U.S. submarines played a continuous supporting effort, one that grew naturally during the war.

Four U.S. submarines, the Narwhal, Nautilus, Seawolf, and Stingray—and eventually more—carried out continuous support operations to Philippine guerrillas from January 1943 through January 1945. There were, in fact, over 40 of these special missions taken by 19 subs, many of which sailed from the port of Darwin in Australia’s Northern Territory. A summary of the submarine missions is detailed in the table. Of the 41 missions, the Seventh Fleet categorized only 3 as partially successful and 1 as unsuccessful (when the sub was lost). Transportation of resistance support via submarine proved successful and only 4 (10 percent) were discovered and attacked by Japanese forces.³⁹

By the time the 6th and 8th Armies invaded the islands, the submarines had delivered hundreds of radios, creating a large intelligence network. Also of importance was the delivery of counterfeit Japanese currency, which allowed guerrillas to pay for local goods and services without the need for promissory notes. In Mindanao, submarines supplied both plates and paper for printing Philippine money—a process approved by Quezon in Washington.⁴⁰ In total, the U.S. Navy delivered an impressive 1,325 tons of equipment via submarine. Moreover, 331 intelligence agents and other personnel were infiltrated to the islands and 472 exfiltrated. Vital items like weapons and ammunition empowered guerrillas to carry out increased ambushes, raids, and sabotage.⁴¹

The Hard-Won Lessons

In hindsight, MacArthur’s approach to guerrilla activities in the Philippines might be construed as reactive and ill-planned. Still, this case study provides excellent lessons about Great Power competition in a contest for supremacy via multiple domains, particularly the maritime. When the U.S. Navy could not readily gain naval supremacy around the islands, supporting indigenous guerrillas proved an excellent alternative to conventional defense. Meanwhile, the geography and populations within the islands offered a powder keg of insurrection that the Japanese were woefully unprepared for. MacArthur’s support to, and sustainment of, violent and nonviolent resistance to Imperial Japan remained an important component to combating the enemy until such time as the United States could regain sea control. When the U.S. Pacific Fleet achieved maritime superiority in late 1944, the Japanese conventional defense of the islands experienced the same doomed fate as the United States had in 1941.

As the Department of Defense considers Great Power competition in the Pacific today, it should adhere to Mahan’s advice by taking a hard look at the pivotal lessons of history. Both maritime geography and diverse ethnolinguistic populations remain dominant considerations in strategy. Competitors such as China and Russia have developed antiaccess/area-denial capabilities with the intention of neutralizing U.S. naval and aerial supremacy in the first island chain. The first chain of major Pacific archipelagos includes the Kuril Islands, the Japanese archipelago, the Ryukyu Islands, Taiwan, the northern Philippines, and Borneo (map 4). While technology has changed, the importance of maintaining sea control remains essential to this theater. Indeed, retention of self-governance on Pacific Island nations will likely require control of sea lines of communications. Like in the Philippines in World War II, the United States can attempt to contest this region with conventional force capabilities, but that effort may prove ineffective, particularly in the short term.

Map 4. First and Second Island Chains

When conventional defense appears unachievable, a resistance strategy can support many U.S. national objectives. The first island chain is inhabited by various ethnicities, religions, and cultures. In cases of foreign occupation, a spectrum of resistance from nonviolent protest through violent insurgency remains likely. A government-in-exile (or a shadow government) could impose obstacles to the legitimacy of an occupying power, undergrounds could sabotage strategically important objectives, spies could provide essential intelligence, and guerrillas could weaken enemy strength. An external sponsor to resistance could greatly aid these indigenous activities—actions which contest the enemy’s purposes despite the loss of sea control. Unfortunately, the United States failed to prepare for resistance opportunities in the Philippines during the Pacific War, but time remains to incorporate such strategies into contingency planning today.⁴² JFQ