The Battle for the Matanikau River, September 27, 1942

          As all of his children and most of his friends know, my father, Zach Davis Cox, Sr., saw action on the South Pacific island of Guadalcanal in World War II and was grievously wounded there. However, it was a fascinating turn of events that led him to a hill behind enemy lines on Guadalcanal on September 27, 1942. This tale involves both what is probably one of the greatest feat of applied mathematics in history and what is the luckiest five minutes in the history of the United States Navy.

          In early 1942 the outcome of World War II and with it the fate of democracy was in doubt. The Axis armies of totalitarian Germany and Japan had enjoyed success after success. The only hope of the free world lay in the advice which Benjamin Franklin had given to his fellow revolutionaries in 1776, “Yes, we must all hang together or we shall most assuredly hang separately.” The importance of this strategy was well known to both the Allies and the Axis powers. In particular, Japan recognized that it could not hope to win a prolonged war of attrition with the Western industrial powers. Japan realized its only hope of retaining any of its newly acquired territories was to divide its enemies, defeat them in detail, and convince them individually to recognize its conquests.

          The key to the Japanese strategy was to isolate and threaten Australia. Japan had already overrun much of the South Pacific and had cut off the western supply lines to Australia by capturing Singapore. But the eastern supply lines from the United States to Australia were still open. The only reason that a country as small as Japan could pose a threat to a country as large as Australia was that a significant portion of Australia’s military forces were helping England fight the Nazis in Europe, Africa, and the Near East. If Japan could sever the lines of supply between the United States and Australia, then the Australia citizens would demand that their armies and navies return home. Disengaging the Australian forces from the war against the Nazis would pose an unacceptable risk to England. When faced with this possibility, England would be forced to sue for peace with Japan on Japan’s terms in order to avoid destruction by the Nazis. If this happened, the United States would have to fight Japan alone.

          In order to achieve this objective, Japan had a two part strategy. First, it had to eliminate the United States’ offensive capabilities in the Pacific. Second, it had to cleave the lines of supply that connected Australia to United States. Elimination of the United States’ offensive capabilities was a straightforward but difficult problem. Japan had to find and destroy the four aircraft carriers in the United States Pacific Fleet. It had hoped to do this in the Pearl Harbor attack on Sunday, December 7, 1941, but all the carriers were away either being refitted on the West Coast or delivering planes to Wake and Midway Islands. Severing the supply lines was similarly a straightforward problem--take and hold an island sitting astride the shipping lanes and use it as a naval and air base to interdict traffic between the United States and Australia.

          However obvious this two-fold strategy is in retrospect, in times of war, military planners are not afforded the luxury of hindsight possessed by modern armchair historians. While the United States did not have a crystal ball to foretell the future, it had a device that was almost as powerful. It is well known that the Allies were successful in cracking the military codes of both Germany and Japan during World War II. The Allies success in breaking Germany’s code was greatly aided by brilliant Polish mathematicians who reverse engineered an early version of German’s cipher devices and smuggled this technology out of Poland in 1939. The United States was not nearly so fortunate in its efforts to crack the Japanese codes. Nevertheless, in an astonishing feat of applied mathematics the likes of which the world has seldom seen, United States cryptologists not only broke the Japanese diplomatic code (Purple) and several naval codes (most importantly JN-19, JN-25, and JN-25b), but actually reconstructed the Japanese cipher machine based on inferences they drew from the form of the encrypted messages. While the German cryptographic devices (and their American counterparts) were based on prewar commercial designs and used electrically wired rotors, the Japanese cipher machine was based on a series of stepping switches of the type used in telephone exchanges of the day. Footnote

          With the aid of the cryptologists, the United States knew how Japan planned to implement its two-fold strategy to force England out of the war in the Pacific. First, lure the remaining U.S. aircraft carriers into an ambush at Midway Island. Footnote

Then with the carriers out of action, capture the island of Samoa. Samoa was ideally suited as a base of operations from which the Japanese could isolate and starve Australia. In regard to the Midway ambush, the United States could only sit and wait for Japan to make its move. But with Samoa, the United States could preempt the Japanese plan.

          In order to prevent the Japanese from taking Samoa, the United States had to occupy and fortify the island. Because the United States was fully committed to a strategy of winning the European War first, it had few military resources which it could send to Samoa. Therefore, the United States decided that it would substitute quality for quantity in the defense of Samoa. That quality took the form of the 7th Regiment of the 1st Marine Division, which was known as “the Old Breed.” Because it was expected that the 7th Marines would see combat first and had the critical duty of holding Samoa against the entire Japanese Imperial Navy, the best and most experienced officers and NCO’s in the entire Marine Corps were transferred to bring it up to full strength. Foremost among the officers on which the 7th Marines’ reputation was built was Lieutenant Colonel Lewis B. “Chesty” Puller, the commanding officer of the 1st Battalion of the 7th Marines. One of Puller’s junior officers was a 22 year-old captain named Zach Davis Cox. Filled with the best the Marine Corps had to offer, the 7th Marines sailed for Samoa from Norfolk, VA on April 10, 1942. Footnote


          With Samoa in the capable hands of the 7th Marines, the United States Pacific Command could devote its full attention to countering Japan’s thrust at Midway Island. In one of the true puzzles of World War II, despite the spectacular success which the Imperial Navy enjoyed at Pearl Harbor as a result of the incredible offensive punch possessed by a task force composed of six aircraft carriers, Japan never again assembled more than four aircraft carriers into a single unit. At Midway, the Japanese apparently believed that four carriers would be sufficient to deal with the two American carriers, the Enterprise and the Hornet, they expected to ambush. The Japanese believed the Yorktown was so badly damaged in the Battle of the Coral Sea that it would be unavailable for use at Midway. But all three carriers lay in wait for the Japanese in the waters northeast of Midway Island.

          Not only did the Japanese underestimate the United States at Midway, but they also committed the fatal error of indecisiveness. After launching an initial air strike on Midway on June 4, 1942, the Japanese had their decks full of planes equipped with torpedoes in anticipation of locating the American carriers. After initial reports of minimal damage on Midway by the first air strike, the Japanese planes were ordered reequipped with bombs for a second attack. Just as the switch to bombs was made, Japanese scout planes located the American carriers and the Japanese planes were ordered back to torpedoes. During this second switch, the Japanese carriers were attacked by American torpedo planes. The American planes, slow and obsolete even before the war started, were no match for the Japanese antiaircraft fire and the nimble Zeros flying defensive patrols. All fifteen torpedo planes were shot down without scoring a single hit on the Japanese carriers. However, while flying to attack the Japanese carriers, the torpedo planes had become separated from the American dive bombers and arrived first.

          This lack of coordination between the torpedo planes and the dive bombers turned out to be one of the greatest strokes of luck ever enjoyed by any navy in the history of warfare. While the antiaircraft fire was focused on the torpedo planes and the Zeros dived down to attack them at sea level, the American dive bombers arrived unnoticed 11,000 feet above the decks of the Japanese carriers, which were full of fully fueled planes being reequipped from bombs to torpedoes. In the space of five minutes, the dive bombers inflected fatal damage on three Japanese aircraft carriers and damaged the fourth, which was sunk the following day. The loss of men, material, and most importantly confidence that occurred during these five minutes was a crippling blow from which the Imperial Navy never recovered. Footnote

          With both aspects of the Japanese strategy for victory blunted, the United States could start thinking about taking the offensive in the Pacific. Because of the vast distances in the Pacific, air power was the key to control of any area. With Samoa now an unreachable objective, the Japanese still wanted a forward air base from which to launch attacks on the supply lines to Australia. The base the Japanese selected was an obscure jungle island in the Solomons named for a town in southern Spain, Guadalcanal. Just as it had done at Samoa, the United States wished to deny Japan a base from which it could interdict shipping. With complete and absolute surprise, the 1st Marine Division, less the 7th Marines, attacked Guadalcanal, seized the partially completed Japanese airfield, and established a small perimeter around the airfield, all with minor opposition.

          Far too slowly, the Japanese came to realize the attack on Guadalcanal was more than a reconnaissance in force. Increasing troop strength slowly and in a piecemeal fashion and never establishing a reliable supply line, the Japanese failed to counter the Marine invasion in a coherent manner. However, the repeated Japanese assaults on the perimeter around the airfield and the debilitating effects of tropical diseases began to take their toll on the 1st Marine Division on Guadalcanal. The Commander of the 1st Marine Division, Alexander Archer Vandegrift, Footnote

needed reinforcements and he knew exactly where to get them. With the threat to Samoa diminished by Japan focusing its attention on Guadalcanal, the 7th Marines were available to be redeployed.

          Immediately upon arrival on Guadalcanal, the 7th Marines went into action, with Puller’s battalion, the 1st of the 7th, in the lead. After successfully acquitting itself in several defensive actions and reconnaissance probes Footnote

, General Vandegrift realized that he finally had the offensive striking force that would allow him to take the battle to the Japanese. Footnote

Five miles west of the airfield was the Matanikau River. The Japanese were accumulating in force west of the Matanikau River and were bringing in heavy artillery with enough range to shell Henderson Field. Footnote

General Vandegrift decided that his first full scale offensive action would be to clear the Japanese from west of the Matanikau and to expand the perimeter enough to put Henderson Field out of range of land based artillery. Footnote

          The offensive strategy employed a three pronged attack on the Japanese position west of the Matanikau. The 1st Raider Battalion and one company of the 1st of the 7th Marines were to attack across the Matanikau at a ford a little less than one mile from the coast. The 2nd Battalion of the 5th Marines were to attack across a sand bar at the mouth of the Matanikau River. After the two main prongs of the attack were across the Matanikau, three infantry companies of the 1st of the 7th Marines, were to be transported by landing craft, known as Higgins boats, to a point behind the enemy lines to cutoff the escape route. These three companies, commanded by Captains Charles W. Kelly, Regan Fuller, and a 23-year-old Zach Davis Cox, were under the overall command of Puller’s executive officer Major Otho Rogers. Footnote

          Sunday, September 27, 1942 was selected as the day of attack. That morning, the 1st Raider Battalion under the command of Lieutenant Colonel Samuel B. Griffith attacked toward the ford across the Matanikau. Unfortunately, the combination of several weeks of hard fighting, debilitation by tropical diseases, and a well dug in Japanese company, the 12th of the 124th Infantry Regiment, prevented the Raiders from reaching the ford. Further complicating the situation, at the same time that Colonel Griffith sent a situation report back to division headquarters, a Japanese air raid occurred. The combination of a sketchy report prepared by a severely wounded Griffith and a further misinterpretation of that report in the midst of the air raid, resulted in a false impression at divisional headquarters that the 1st Marine Raider Battalion had taken the ford and crossed the Matanikau. The crossing of the Matanikau by the Raiders was the signal for the 2nd Battalion of the 5th Marines to cross the sandbar at the mouth of the Matanikau and for the three companies of the 1st of the 7th Marines to proceed by Higgins boats to cut off the Japanese retreat.

          The 1st of the 7th Marines landed behind enemy lines without opposition and quickly moved to occupy the high ground from which they could bring mortar fire on any retreating Japanese. Only none were retreating. The 12th Company stopped the 1st Raiders cold at the ford. Similarly, the 9th Company of the 124th Infantry Regiment prevented the 2nd of the 5th Marines from crossing the sand bar. Realizing that he had a significant force of Marines trapped unsupported behind his lines, Colonel Akinosuku Oka, commander of the 124th Infantry Regiment, ordered the 2nd Battalion of the 124th Infantry Regiment to attack the trapped Marines. Intent on destroying the Marines, Colonel Oka ordered portions of the 9th and 12th Companies to depart their positions at the ford and mouth of the Matanikau and to attack the trapped Marines.

          In a short time, the three companies of the 1st of the 7th Marines were surrounded and attacked from three directions by a force of Japanese five times their number. A Japanese mortar round landed between the legs of Major Rogers and literally blew him to pieces. Shrapnel from this same mortar round seriously wounded Zach Cox. Footnote

Zach’s wounds, starting at his head and continuing down, were as follows. Shrapnel and the concussion from the exploding mortar cracked his skull and blew several shards of metal into his brain. Shrapnel tore open his left upper chest, caused multiple and compound fractures of his left shoulder and left arm, and deflated his left lung. The concussion broke his back in three places. The flash from the blast burned the entire left side of his body as well as all the hair from his head. Footnote

          Zach Cox’s wounds were so severe that little could be done to help him. The expediency of war necessitated the creation of a medical strategy known as triage. In triage, the wounded are divided into three categories: those wounded so slightly that they will survive without immediate attention, those wounded so severely that they will not survive despite immediate attention, and those while severely wounded, will survive if given immediate attention. Under the triage strategy, those falling into the third category are the first treated. Zach’s wounds were so severe that he was consigned to the second category, those who cannot be saved. Zach was given a shot of morphine and had his wounds bound, but was not otherwise tended to. While this lack of attention left Zach with diminished chances for survival, it also left him free to continue in the defense of the position.

          This defense was entirely dependent on fending off Japanese attacks until help could arrive. Portable radios in the early days of World War II were heavy and notoriously ineffective. The Marine signalman attached to the three companies, Sgt. Robert D. Raysbrook, had not brought the radio because he believed both that it would not work and that it might be a hindrance in a fight. Therefore, these three companies found themselves completely surrounded by a force five time their number without the means of summoning help. However, the decisive and timely actions of two persons intervened on their behalf and averted disaster.

          General Vandegrift had forbidden the battalion commander, Lewis Puller, from accompanying his three companies behind enemy lines because his expertise was needed at the operations center in the divisional headquarters. It didn’t take Puller long to realize that the 1st Raiders had not crossed the Matanikau. Upon realizing that the 2nd of the 5th Marines were not going to cross the Matanikau at its mouth, Puller knew that his three companies were in mortal danger. Footnote

Puller’s fears were confirmed by Second Lieutenant Dale Leslie. While flying over the cutoff Marines in an observation plane, Lieutenant Leslie saw that the Marines had spelled out “HELP” on the ground with their white t-shirts in order to attract his attention.

          Based on his own intuition and Lieutenant Leslie’s report, Colonel Puller boarded the destroyer Monssen and proceeded to the relief of his men with several Higgins boats in tow. Footnote

Realizing the severity of his wounds, Zach had turned over command of his company to his executive officer. However, unwilling to disengage completely from the battle, Zach tracked down Sgt. Raysbrook, who had left the radio behind. When the Monssen appeared off the coast, Captain Cox directed Sgt. Raysbrook to stand up on an exposed stump and communicate with Puller the Monssen. With Japanese bullets whizzing by him, Sgt. Raysbrook repeatedly stood his ground and sent messages via semaphore signals and received messages from Puller via a signal blinker. Footnote

Puller ordered his men to the coast. The reply was that they were too heavily engaged to reach the coast. Puller responded that the coast was their only hope. Once convinced that Puller’s advice was their only option, a barrage of shells from the 5-inch guns on the Monssen rolled up to the Marines’ position. Then the barrage retreated to the beach. In the wake of the barrage, the Marines attacked toward the coast. Footnote

          As the Marines fought their way to the coast, Platoon Sergeant Anthony P. “Ski” Malanowski, Jr., an expert with a Browning Automatic Rifle, ordered his platoon to continue on while he remained behind to delay the pursuing Japanese. This delay allowed the Marines to reach the beach, but Sergeant Malanowski didn’t. He was posthumously awarded the Navy Cross. While fighting their way to the beach, the Marines had drifted to the east of the position where they had landed. This meant that the Higgins boats didn’t know where to pick them up. Once again, the Marines’ guardian angel in the air, Lieutenant Leslie, intervened. Seeing that the Higgins boats were headed to the wrong position, Lieutenant Leslie got their attention and led them to where the Marines would reach the coast. Footnote

          Zach Cox was helped from the high ground back to the beach by the youngest man in the 1st of the 7th Marines. This man had lied about his age in order to enlist. By the time his ruse was discovered, he was old enough to join and had proved his fitness, so the Marines decided to overlook the circumstances of his enlistment. As they got close to the beach, Zach’s strength failed him, and this young Marine had to carry him on his back. Zach Cox still bears the scars on both sides of his right calf where the Japanese machine gun bullets passed through his leg and killed the young Marine who had saved his life.

          Once at the beach, the Marines boarded the Higgins boats under heavy fire. With one Higgins boat still ashore, there was only one man left alive on the beach, Captain Zach Cox. He was so debilitated by his wounds and the exertion of getting to the beach, that he was crawling to get to the Higgins boat. The men in this last Higgins boat were Marines from the company that Zach had trained in Cuba and Samoa. He had drilled them mercilessly, marching them mile after mile, training them at night, and exercising them under the blazing tropical sun. He trained his men so hard that they nicknamed him “Rawhide.” The training was so intense that his First Sergeant warned him that if he didn’t ease up, he was going to be the first person shot once they got into combat.

          But he wasn’t. Two men sprang from the Higgins boat and were quickly cut down by the Japanese fire. Footnote Two more men dashed forward, reached Zach, pulled him to his feet, and got him aboard the boat. Footnote

Seeing the plight of this last Higgins boat, another boat piloted by Coast Guard Petty Officer Douglas A. Munro interposed itself between the Higgins boat and the area from which the greatest concentration of Japanese fire was coming. Petty Officer Munro was killed while directing the fire from the two machine guns on his boat at the Japanese position. Petty Officer Munro was posthumously awarded the Medal of Honor. Footnote

          With a loss of eighteen men killed and twenty-five wounded, the 1st of the 7th Marines had successfully fought their way through an enemy force at least five times their number and evacuated the beach. The official report of the 1st Marine Division attributed the successful withdrawal of the 1st of the 7th Marines to “its fighting qualities, brilliant improvisation on the part of those responsible for its movement and to the great good fortune which attended it.”

          Even after being transported back within the perimeter surrounding Henderson Field, the vital but merciless rule of triage again dictated that the severity of Zach’s wounds were beyond treatment. Still bound in his field dressings and unconscious from shock, he was consigned to a tent reserved for the dead. Eventually Zach regained consciousness, started moaning, and terrified a passing Navy corpsman. Upon determining that it took more than a Japanese mortar to kill a Marine, the Navy doctors and corpsmen treated Zach and directed his immediate evacuation from Guadalcanal. Footnote

          After a brief stop at the nearest field hospital, on Espiritu Santo Island, Zach was sent to New Zealand for treatment beyond what was available at the front. But the only transport available was a cargo ship. Because of the danger from submarines, the ship’s captain refused to allow anyone on board who was unable to care for himself. The test for self-sufficiency the ship’s captain employed was that all persons boarding the ship had to walk up the gangway. Knowing that Zach was in such bad shape that he had to be evacuated, the Navy doctors pumped him full of enough morphine to stun an ox and then pointed toward the gangway. Footnote

Zach staggered onboard and once out of sight of the captain was quickly rushed to the ship’s galley that was serving as a makeshift hospital ward. Unfortunately, the disaster the ship’s captain had foreseen came true and the ship was torpedoed. Zach was helped to the main deck, but he lay down there because knew he would never be able to clamber down a cargo net to the life boats below. He said he remembered thinking while looking up at a beautiful night sky full of stars that it wouldn’t be so bad to die. But eventually, a corpsman returned for him and requested that he at least try to get into a lifeboat. With the corpsman’s help, Zach arose, but he remained sure that once he got to the railing the futility of his trying to board a life boat would be obvious. However, by this time the ship was so low in the water that he was able to step directly from the main deck to a lifeboat. After spending several hours adrift and beating off sharks attracted by the blood from the wounded, Zach and the others in his boat were picked up by another ship and his journey to New Zealand continued.

          His recovery proceeded in three phases: New Zealand, San Francisco, and Norfolk. In New Zealand, in addition to having his wounds cared for, he was also treated for filariasis malaria and blackwater fever, both contracted while on Guadalcanal. Zach’s blackwater fever was diagnosed by a Navy physician who, by sheer chance, had read about this usually fatal complication of chronic malaria just a few days before. Footnote

After recovering sufficiently, he was transported to the Naval Hospital in San Francisco. There he was joined by his bride of less than a year, Mary Gwin Oliver Cox. As soon as possible, Zach was given married housing with his wife. However, he still had to report to the hospital on a daily basis for treatment. Footnote

After treatment in San Francisco, Zach was promoted to Major and was assigned first to Norfolk Naval Ship Yard and then to Parris Island Recruit Training Depot until his injuries fully healed. Once healed, Zach returned to the South Pacific and participated in the campaigns for the Marshall and Northern Mariana Islands. Footnote

          When the atomic bombs were dropped on Japan to end World War II, Zach was at Camp Lejeune training for an attack on a fortified coastal cliff on the southernmost Japanese home island of Kyushu. After the end of the war, Zach went with the 1st Marine Division to China, where it oversaw the disengagement of the Japanese Army from mainland Asia. After successful completion of that task, Zach returned to the United States to face a fitness report. While his service record was spotless, Zach was caught in a massive demobilization. The severe wounds he received on Guadalcanal made him a prime candidate for retirement on medical disability.

          Despite his pleas and calling in every favor he had accumulated during the war, there were just too many officers and too few slots. Even Lewis Puller was forced into the reserves. After accepting the inevitability of his retirement, Zach served out the remainder of his service in Norfolk defending Marines and Sailors being court-martialed for petty offenses by overzealous officers seeking to restore pre-war order to the military.

          After retirement, Zach and Mary Gwin returned to their hometown, Mt. Olive, NC. He built a home next to his father’s house and went to work with his uncle in the wholesale grocery business. Zach and Mary Gwin, neither of whom were college graduates, had seven children and so instilled the importance of education in them that all seven graduated from college. Footnote

          Zach Cox was not a hero of World War II. He was just an ordinary soldier doing his duty like millions of other young American men. Footnote

Each of those men was willing to give his life to defeat one of the most monstrous combinations of evil to have ever walked the face of the Earth. Each of the Axis powers was founded on the lie of racial superiority and believed that abomination justified its atrocities against mankind. The efforts of Zach Cox and others like him conclusively refuted the lie of racial superiority and forever demonstrated that those who practice evil will be held accountable for their misdeeds by the people of the world.

          To this day, Zach Cox still wakes up in the middle of the night shouting orders to men long dead, while in the embrace of nightmares about now obscure South Pacific islands.