*This alternate history has its point of divergence in 1917, so reference historical sources for any and all information before that point.
- War is Declared
In 1930, Japan is in the final stages of preparations for war with the Sino-German alliance. The troops of the Kwantung Army, responsible for the invasion of Manchuria and the remainder of China, is mustered in advance bases in southern Manchuria. Although the region is under de jure Chinese control, the southern and eastern portions are de facto controlled and administered by Japan. The Japanese base at Dairen on the tip of the strategically critical Liaoning Peninsula is of vital importance to both sides.
The port, formerly known as Port Arthur during its days as a Russian territory, was taken by Japan during the Russo-Japanese War. In 1930, it is home to the Japanese Western Squadron, responsible for the YellowSea and the Bo Hai Sea. However, in the event of war, the Sino-German alliance cannot allow the Japanese to launch raids, especially submarine raiders, from this port into the heart of Chinese trade. That seems to be exactly what the Japanese are preparing for as Chinese air patrols spot unusually high Japanese naval traffic along the Korean and south Manchurian coasts, all heading for Dairen. Among this traffic are not only the expected light raiding ships, but also many capital ships. This signaled to the Sino-Germans that the Japanese could be planning a major fleet action. A Japanese victory in such a battle could mean major bombardments of the Chinese coast and a complete bottleneck on Chinese overseas trade and, therefore, an isolation of Chinese ground forces.
To counter the growing threat, the German and Chinese governments and militaries authorize increased numbers of sea patrols, mostly by destroyers, in an attempt to scare away any lurking Japanese submarines. In April 1930, the Japanese begin to take notice of the growing Chinese and German naval traffic in the Yellow and Bo Hai Seas. Heated debate between Japanese leaders ensues over whether to continue to reinforce the Dairen base, likely provoking a war, or to cease the reinforcements and allow the war to begin on Japan’s terms. The Japanese plan is to fabricate an explosion on a railway bridge in southern Manchuria, blame it on the Chinese and the Germans, all while the moving Japanese troops forward in order to begin the war with the momentum on their side. After days of debate, it is deemed that the Western Squadron at Dairen (now the size of a true fleet) is large enough to hold its own and, after all, it is more important that the war begin on Japan’s terms. The decision is made to stick to the original plan and cease the reinforcements to Dairen.
The Japanese have made a fatal miscalculation. The assumption is that the Sino-German alliance is not willing to be seen as the aggressors in the upcoming war whereas the Japanese are already isolated on the world stage and have nothing left to lose by being the aggressors. However, the Chinese and Germans know that, due to Japan's woeful reputation, any preemptive action taken against the Japanese will be seen as completely reasonable, warranted, and proportional to Japan’s provocations. So, the German and Chinese militaries, with the authorization of their governments, finalize their plan for an attack on Dairen.
On 1 May 1930, at 7:30 pm, the German East Asian Fleet and the Chinese Northern Fleet slip out of their respective bases at Tsingtao and Tientsin. Sailing through the Bo Hai Sea overnight, they rendezvous off the coast of the Liaodong Peninsula at Dairen. At the same time, a landing force is departing Qinhuangdao bound for beaches the northern coast of the Liaodong Peninsula, opposite Dairen, on the southern coast. The plan is for the combined Sino-German Fleets to launch a surprise bombardment on the Japanese fleet at anchor in Dairen harbor. When the Japanese fleet is destroyed or has surrendered, the Sino-German fleet will sweep the harbor for mines while the capital ships bombard the Japanese positions on the outskirts of the city. By the time the bombardment of the Japanese defenses begins, the amphibious assault, numbering 30,000 in several waves and made up of elite German Seebataillon units and the German-trained Chinese Naval Infantry, will be in position to launch an attack on the surprised and hopefully broken Japanese garrison division, numbering under 15,000. At 6:00 am on 2 May, With the forces in position awaiting the hour of attack, the German and Chinese ambassadors deliver declarations of war to the Japanese government in Tokyo and the attack on Dairen commences.
II. The Opening Salvos
At first light, the first salvos are fired from the German and Chinese battleships and battlecruisers into the surprised Japanese fleet moored in Dairen. Torpedo and dive bombers from the German aircraft carrier SMS Held eliminate the Japanese airbase near Dairen, ensuring air superiority. The Japanese fleet tries to weigh anchor and sail out to face the ambushing force but, amidst the destruction and confusion, several ships run aground and collide with each other, or worse, with mines laid by their own ships to protect the harbor. At 9 am, the Japanese Western Squadron is utterly devastated. All battleships and battlecruisers along with most cruisers are sunk, run aground, or damaged beyond repair. The valuable aircraft carrier that had been assigned to the squadron lays on its Portside at its mooring.
At 9:30, Vice Admiral Hermann von Bauer, commander of the combined Sino-German fleet, gives the order to commence firing on the defenses to the north of the city in order to support the amphibious assault. By this time, the amphibious force has already landed and its vanguard is making its way, with minimal resistance, towards Dairen. By midday, the city’s outer defenses are being pummeled from behind by the Sino-German fleet and from the front by the amphibious force’s artillery, just arrived from the landing zone. For the rest of the afternoon, the Japanese mount a stiff defense, falling back to their second and then third lines of defenses but there are just too few troops to counter the relentless push and bombardment of the Sino-German forces. With evening descending, the still somewhat stunned Japanese military governor of the city is convinced by his subordinates to spare his forces a house to house battle and he surrenders.
The Japanese government in Tokyo is stunned by the dramatic turn of events but is more resolved than ever to punish their enemies. With the the Japanese possessions on the Liaodong Peninsula, including the base at Dairen lost, the Japanese naval forces can no longer directly threaten the important cities on and near the Bo Hai Sea. The navy also cannot support the Japanese ground offensive in Manchuria. Due to these factors, the Japanese high command begins to plan for another naval engagement, this time on Japan’s terms. However, the Japanese fleet is wounded and this offensive is far off yet.
Soon after the victory at Dairen, the Russian Republic, which had originally hesitated to honor its alliance with China and Germany, voted to declare war on Japan. Their original apprehension was likely due to the scarring memories of the Russo-Japanese War twenty-five years earlier, however this new war provided a chance for redemption and a proof of legitimacy of the still young Russian Republic and its military. The Russian Army of Manchuria, split between Khabarovsk and Ussuriysk and numbering about 400,000, is under the command of General Lavr Georgiyevich Kornilov. The Russian plan, agreed upon by China, Germany, Russia, and the US (henceforth known as the Allies) before the war, was for a two-pronged attack directed at the heart of Manchuria, namely the city of Harbin. The Khabarovsk Army would push southwest along the Amur River (known in Manchuria as the Songhua River) towards the objective while the Ussuriysk Army would push northwest. Following the fall of Harbin, the united Russian Army of Manchuria would continue to push southwest along the Southern Manchuria Railroad from Harbin all the way to Changchun and Mukden. Along the way, they would unite with the Sino-German forces moving northeast along the same railroad from the now Sino-German-held base at Dairen.
The first task of the Japanese is to launch their ground attack in Manchuria. However, before the Japanese can know this is safe, they must bottle up the Sino-German forces on the Liaodong Peninsula. If these forces break out of the peninsula in open ground in Manchuria, Japanese forces invading China can be attacked from behind and surrounded and the path to Korea would be open. To accomplish this, on 4 May, a 100,000 strong detachment, including an armored unit, is sent south from the nearly 700,000 strong Kwantung Army. The original landing force, numbering about 30,000 Chinese Naval Infantry and German Seebataillon troops, had, since taking the city, received 15,000 regular Chinese infantry and artillery as reinforcements, and had begun to move north, consolidating control of the peninsula and attempting to break out in open ground.
However, the Sino-German intelligence had underestimated the strength of the Kwantung Army by several hundred thousand and had, therefore, underestimated the size of any detachment the Japanese might send to counter the attack on Dairen. Additionally, the Sino-German alliance had failed in the days following the initial victory to send any armored or mobile units to the peninsula. So, on 7 May, the Sino-German advance meets the Japanese counterattack on the road to Wafangdian. While the Sino-German force fights valiantly, it cannot overcome the Japanese advantage in numbers. Additionally, the Japanese units are of higher quality than those of the Chinese due to their experience in the frontier posts of occupied parts and Manchuria and Korea. After suffering heavy losses, the depleted Allied force fights a rearguard action while falling back to the bottleneck that separates the narrow tip from the wider section of the Liaodong Peninsula. The Allied fleet in Dairen harbor makes it impossible for the Japanese counterattack to try to push through the bottleneck due to the range of the naval guns. After the action, the Allied force is relegated to holding the bottleneck while the Japanese force, although powerless to attack this Allied force, makes it impossible for the force to break into open ground and threaten the main Japanese advance.
And so end the opening moves of the war: a significant Allied victory mitigated but not negated by a strong Japanese counterattack, Japanese forces of the Kwantung Army concentrating for an offensive into China, Russian forces concentrating for an attack into Manchuria, and the Japanese and Allied fleets staring each other down across the Yellow Sea, each waiting for the other to make the first move.