This continues a series at the Diplomat on significant counterfactual scenarios in Asian history. See the first installment on Chiang Kai-shek’s victory in the Chinese civil war, the second on the United States using nuclear weapons during the Korean War, and the third on Japan’s victory at the Battle of Midway.
The Pacific War is known for its naval battles and brutal island slogs. The battles of Iwo Jima, Midway, and Bataan have taken near-mythical places in U.S. military history, with good reason. Much of this is due to the common perception that the Pacific War was mainly a duel between the United States, China, and Japan, and that other actors were effectively knocked out of the war in 1941. Although this is mostly true, Australia played a particularly crucial role in the war against Japan. Australian soldiers, airmen, and sailors fought Imperial forces from the Malaya Campaign in 1942 to the Japanese surrender in September 1945.
One of the most significant and equally unknown battles (outside of Australia) of the war took place in the hostile unmapped interior of Papua New Guinea. Over the course of three months in 1942, a couple thousand inexperienced and poorly equipped Australian reservists fought a detachment of elite Japanese soldiers to a halt. The battle has faded in comparison with the more climactic battles at the Coral Sea and Midway, but actually represents a crucial turning point in the war. Combined with these two victories, the Kokoda Trail Campaign marks the point at where Japan lost the strategic initiative to the allies. From then on, it would fight a defensive war right until the destruction of Hiroshima and Nagasaki in August 1945.
In the Collected What If?, the American author James Bradley presents a horrifying overview of the battle, as well as some ideas of what would have happened if the Australian soldiers had lost the battle, as most military logic dictated that they should have. The Battle of Kokoda Trail is mostly unknown outside of Australia, but the implications of a counterfactual Japanese victory would have had wide-ranging consequences for the Pacific War.
After their surprise attack on Pearl Harbor on December 7, 1941, Japan enjoyed six months of triumph. Launching lightning campaigns throughout Southeast Asia, the Imperial army and navy quickly overran the European and American possessions. A U.S. army surrendered in the Philippines, marking the worst U.S. defeat in history. Pre-war Australian war plans had depended on the British fleet shielding it from any potential enemy. For that reason, Australia sent most of its professional army to fight the Germans and Italians in North Africa, leaving the country almost stripped of local defense forces. With the fall of Singapore and the sinking of the Royal Navy’s battleship HMS Prince of Wales and battlecruiser HMS Repulse on December 10, 1941, that strategy evaporated.
By mid-1942, the situation for Australia was grim. Although U.S. General Douglas MacArthur had relocated his headquarters to Brisbane and American supplies and reinforcements were trickling in, Australia was looking increasingly isolated and vulnerable. Australia was provisioned through a tenuous supply line stretching from the country’s eastern coast, past the islands of Fiji and Samoa to Hawaii and California. If the Japanese were able to cut that line, Australia would be at the tender mercies of the Imperial Navy.
Japan was well aware of Australia’s predicament. Under the leadership of the formidable Admiral Isoroku Yamamoto, the Japanese had planned the occupation of Fiji and Samoa, unimaginatively named Operation FS. If successful, Operation FS would achieve two strategic objectives for the Japanese: First, it would critically isolate Australia, whose northern coast was only a few hundred miles from Port Moresby. This could have forced Australia to withdraw from the war, or in the worst case, even suffer partial invasion. Second, the conquest of Fiji and Samoa could be the start of Japan’s own island-hopping campaign, with Hawaii as its ultimate goal. (According to Professor John J. Stephan at the University of Hawaii, this so-called Eastern Operation was considered by a number of Japanese naval officers, perhaps including Yamamoto himself, as the only way the United States would agree to a negotiated peace with Tokyo.)
The success of Operation FS hinged on one crucial outcome: the occupation of Port Moresby on Australian-controlled Papua New Guinea. This city provided an important supply post for allied warships and aircraft in the region. If it could be taken from the allies, the Imperial navy could use the port and airfield to support its advance in the South Pacific, raid the Australian coast, and deny its use to the Americans and Australians. The first attempt to take the city was foiled at the Coral Sea, in which the Japanese and Americans each lost an aircraft carrier. Although the Imperial navy failed to capture Port Moresby, the Japanese general staff was emboldened by what they thought was a great victory, believing they had sunk two U.S. carriers. (Although the Imperial Navy was able to sink the USS Lexington, the USS Yorktown was merely heavily damaged in the battle, and was able to limp back to Pearl Harbor. Repair crews were able to miraculously repair her sufficiently for her to take part in the critical Battle of Midway.)
One month later, at Midway, the Imperial navy suffered an overwhelming defeat, losing all four of its carriers in return for just one American carrier, the hastily repaired Yorktown. Although this defeat cancelled Operation FS for the time being, capturing Port Moresby remained a key objective. Even if the occupation of Fiji and Samoa proved untenable for the time being, capturing Port Moresby would seriously impede any allied island-hopping strategy and continue to pressure Australia.
Since the Imperial Navy had failed, Japanese general staff concluded that the best way to capture the city would be a 100-kilometer overland march from Gona, through the forbidding Owen Stanley Range in central New Guinea. This offensive would follow the Kokoda Trail, basically a mud track, which at its highest reaches over 2,000 meters above sea level. The trail is still a brutal march today, with several guest houses and developed infrastructure, including airfields. In 1942, it was hellish, with unbridged rivers, precipitous cliffs and, not least, unknown tropical diseases. The locals were also much less inclined to be hospitable then; the Kokoda Trail cut across territory inhabited by cannibal headhunters (as late as January 2016, two Westerners were kidnapped and tortured by cannibals while trekking the Kokoda Trail*).
The Japanese sent some of their best troops for the march. Led by the experienced Lieutenant-General Horii Tomitaro, the so-called South Seas detachment consisted of some of the finest troops in the Imperial army, veterans of the jungle campaigns in Indonesia and Malaya. Furthermore, they had aerial dominance by virtue of their superior aircraft. To oppose them, Australia sent raw recruits. The 39th Infantry Battalion consisted of militia troops — conscripts who had been given minimal training, outdated weapons, and utterly inadequate desert khakis. Even worse, the battalion had not been issued any weapons with more firepower than a machine gun and suffered a severe shortage of ammunition. The Japanese, on the other hand, were equipped with specially designed lightweight mortars, carried plenty of ammo, and wore jungle uniforms.
The Australian soldiers were told to rush to “the Gap,” a supposedly narrow valley about halfway up the track, where the terrain allowed for strong defensive positions. The Australian militiamen soon learned the value of that advice. “The Gap” was a valley seven miles wide, and was initially held by 75 Australian and local troops. These two platoons were soon attacked by over 500 Japanese soldiers. These vastly outnumbered Australian soldiers were able to inflict such heavy casualties on their enemy that the Japanese reported that they were facing over 1,200 enemies. After a day of heavy fighting, the Australians withdrew down the trail, while the exhausted Japanese were unable to pursue them. After several days, Australian reinforcements trickled up the trail and, after three months of hard jungle fighting, in which many soldiers died from disease and exposure to the extreme climate, the Japanese finally withdrew to Gona. At their offensive’s farthest point, the Japanese were so close to Port Moresby that they could see the city lights at night.
Despite their bravery, MacArthur told his superiors in Washington that the Australian soldiers “lacked fighting spirit.” Considering their woefully inadequate training, equipment, and the experienced enemy, fighting spirit is all those men had.
As opposed to the other counterfactual scenarios in this series, an alternative outcome of the Kokoda Trail campaign relies more on military logic than the decisions of one person. The Imperial Army had beaten their Western opponents at almost every turn, especially on a jungle battlefield. They brought better weapons and supplies to the fight, and were led by competent officers. At any point during the battle, especially during the first weeks when they outnumbered their enemy significantly, the Japanese should have been able to roll up the Australian militiamen. This is where our first-order counterfactuals begin.
Let’s say the Japanese troops were able to rout the Australians at “the Gap” during the first days of the fighting. Through superior firepower and more mobile troops, this is entirely plausible. With old and often malfunctioning radios, the Australians were completely dependent on runners to keep their superiors informed. This often resulted in severe delays in the transmission of orders, which means that after the initial defenses had been routed, Australian reinforcements would have run right into Japanese troops marching down the trail toward Port Moresby. It is not implausible that the Imperial Army could have taken the city within weeks, if not days.
Here our second-order counterfactuals begin. With Port Moresby in the Imperial Army’s hands, the Japanese would have been able to reinforce their position by air, sea, and, to a lesser degree, land. Considering that the allies would have no close airbases or anchorages to resist the Japanese, most of the southern coast of New Guinea would have been conquered. With the coastal areas of New Guinea under firm Japanese control, any U.S. advance through the Solomon Islands, as actually happened, would have been hugely difficult, if not impossible.
What next? With four carriers sunk at Midway, it’s doubtful that Imperial navy would have the capacity to launch a renewed Operations FS. However, from New Guinea, the Japanese would have been able to launch attacks against Australia. Most significantly, this could have affected Australia’s tenuous supply line to the United States. From Port Moresby, Japanese aircraft and submarines could have exacted a heavy toll on allied shipping, depriving Australia of essential supplies and resources.
The Japanese air force and navy could also have carried out attacks on Australia itself. Like the raid on Darwin on February 19, 1942, these attacks would probably have a large psychological effect even if their physical impact would be quite insignificant. This could have forced Canberra to withdraw its troops fighting in other theaters, such as North Africa and Burma, weakening allied forces elsewhere. If the Japanese had been able to effectively isolate Australia, there is a possibility (admittedly unlikely) that Canberra might have tried to come to terms with Tokyo.
Bradley suggests that Japan might even have attempted a partial invasion of Australia after the conquest of Papua New Guinea. According to the Swiss historian Henry Frei in Japan’s Southward Advance and Australia: From the Sixteenth Century to World War II, an invasion of Northern Australia was proposed by several member of the Japanese general staff, especially in 1941. Ideally, this would have happened after the completion of Operation FS and the destruction of the American carrier fleet in the Pacific. However, a Japanese invasion of Australia after the fall of Port Moresby seems highly unlikely. The sheer size and scattered population would required a huge investment in troops, shipping, and warships. With the American navy triumphant at Midway, U.S. carriers could have intercepted an invasion force. In any case, both Yamamoto and Prime Minister Tojo Hideki were opposed to such invasion plans. It is probable that the only thing that could have changed their minds would have been if the Imperial Navy had been able to destroy their American counterparts at Midway.
Like my previous article in this mini-series, a counterfactual Japanese victory would probably not have changed the final outcome of the war. U.S. industrial potential, the nuclear bomb, and the Soviet Union’s entry into the Pacific War would have resulted in an allied victory, eventually. However, those brave Australians on the Kokoda Trail might have saved their country from even more hardship than it endured during the war and, ultimately, may have even shortened the Pacific War considerably.
*Serious doubts have been raised about the veracity of the kidnapping story.