The Northern Expedition
"Western journalists, in their hubris and naivety, have drastically misunderstood Chinese politics. [...] Just last week, the New York Times called Zhou Enlai the 'Most Dangerous Man in China'. This could not be further from the truth. In actuality, Zhou Enlai is, by far, the most dangerous creature on the face of the Earth".
-Chiang Kai Shek
Wang Jingwei had his work cut out for him. The Zhili had achieved control over the northern part of the country, having decisively crushed every army that stood against them. At the same time, the right-wing faction of the KMT, led by Chiang Kai-shek, was power-hungry and anxious to replace Wang. Nevertheless, the Republic had a much better trained, equipped, and organized army than the Zhili, who had still not recovered from their various wars against rival factions in the North. The Beiyang government also had concerns about the dubious loyalty of the warlords further South, fearing that they may abandon Wu Peifu should the winds change.
The Republic's invasion plan consisted of two different armies that would advance into Zhili territory. The first, under the command of Li Zongren, contained about 110,000 troops and would race up the coast towards Shanghai. Meanwhile, a western army of around 120,000 would advance on Wuhan in the Western theater of the war, before turning northeast and attacking Nanjing, where they would be joined by Li Zongren. Once their objectives were secured, the forces would go north in pursuit of the ultimate prize, Beijing itself.
The early days of the invasion went well for the Republic. Zhili concerns about treacherous warlords in the border region were realized, and many of them defected to Wang's government after brief struggles. Li moved rapidly up the coast, running into little resistance until he reached Taizhou, about 120 miles south of Shanghai. An army of 50,000 soldiers had been deployed south of the city, cutting off the Republican's advance. Due to their numerical superiority, Li chose to attack first. The Zhili army was quickly pushed back into the city, where they regrouped north of the Jiaojiang River. At this point, it became clear to Li that this had been their plan from the beginning, and that the Zhili were trying to lure them into attempting a crossing. Instead, he decided to circumvent the river, by taking 90,000 of his soldiers several miles west to circle around and attack from the North. After spending several days navigating the highlands west of the city, Li returned to Taizhou, only to find that 40,000 of the soldiers had been moved north, out of the city. Exasperated and eager to pull the Zhili into a direct confrontation, Li continued towards Shanghai.
En route to Shanghai, the army was continuously harassed by small militias loyal to Wu Peifu, who raided camps, gathered intelligence, and cut supply lines. The Zhili, being the most liberal of the three Beiyang factions, had some support from the local populations. Many local peasants were Republican sympathizers, but did not contribute intelligence and resistance like Wang had hoped. Villages did not take strong steps to prevent anti-Republic sabotage by Zhili agents, and made only half-hearted attempts to bring them to justice after the fact. This greatly frustrated Li, who would arrive in Shanghai nearly two weeks later than expected at the beginning of the campaign. These two weeks proved vital to the Zhili defense of Shanghai, who had been deliberately obstructing the Republican's march north in order to buy time. Walls, trenches, and armaments had been constructed running from Taihu Lake to Hangzhou Bay, promising a bloody struggle to advance into the city proper. Li's intelligence informed him that the plains west of the Taihu and south of the Yangtze had been heavily mined. 70,000 soldiers defended the city from within, with mountains of supplies, weapons, and ammunition.
Zhou Enlai, a native of the region and lieutenant under Li, had been educated in Europe and was familiar with trench warfare. Lacking the tanks that would be necessary to break the stalemate in that matter, Zhou devised an infiltration strategy to breach the southern defenses. Once this was accomplished, the KMT would use their superior numbers to corner the Zhili in the city, killing or capturing the majority of the army. In the beginning, the Battle of Shanghai went as planned for the KMT. The Zhili seemed unprepared for their deft implementation of anti-trench tactics and ruthless exploitation of gaps in the 47 mile defensive perimeter. Even still, Li was unable to beat the defences and enter the city before the beginning of October. Shanghai had a mild climate, so the winter was not of real concern to attackers, but the failure to score a single decisive victory over the Zhili for the entire Summer was demoralizing.
The Western front of the war saw the quick conquest of Wuhan after a minor struggle with local warlord Jin Yaojing. The army advanced towards Nanjing, and was confronted by an army of nearly 200,000 hastily assembled troops to stop them. Their commander, Sun Chuangfang, was Wu Peifu's protege, and had experience in the earlier years of the Warlord Period. Despite their numerical advantage, the Zhili army was under equipped, and many had completed only minimal training. The battle was fought in the shadow of Tianzhu Shan, the tallest mountain in the Dabie Range. Sun Chuangfang and his troops fought valiantly, but they couldn't resist being overwhelmed by the superior by the clearly superior Southern forces. Still, it was hardly an easy victory for the Republicans, who lost 30,000 troops and found themselves stranded in the mountains with no easy routes for supplies. Hopes of quickly capturing Nanjing and then proceding to assist Li's army in Shanghai were extingushed. The Western Army regrouped in the Anhui province, then continued towards Nanjing slowly and cautiously.
Despite their overwhelming numerical advantage, the Zhili had been reluctant to commit too many troops to halting the invasion, instead using resources defending against Ma, Anhui, or Fengtian invasions. After the defeat of the Fengtian, the Zhili had also become concerned that Japan might intervene directly. A foreign invasion during the war with the KMT would be a nightmare scenario for Wu, and he left a sizeable army on the Korean border in preparation for such a contingency. Another fear Wu had was that the KMT might make a drive directly for Beijing, disregarding major cities in the South. Control of Beijing was important to the Zhili for several reasons. For one, it legitimized them in the eyes of the lower classes, and meant they were perceived as the legitimate government rather than a rebel uprising like the KMT. This was also of vital importance of securing the alliegance of smaller warlords in the peripheral regions. Further, the Beijing government was the sole recognized government of China to foreign states, which meant that the Zhili could take out loans from other states and received some weapons and funding from Western states. Losing this legitimacy could be catastrophic to the Zhili war effort.
Fortunately for the Zhili, by the end of 1926 the KMT had shown its hand. A rapid victory was no longer possible, and the Zhili held the advantage in the event of a protracted war. There was still a possibility, believed Wang, that the KMT could break through Shanghai's defenses and route the Zhili while avoiding a war of attrition. The internal conflicts of the KMT were not making this easy, however. Wang lived in fear of a right-wing coup orchestrated by Chiang Kai Shek. In order to prevent this, he had marginalized right-wing politicans and military commanders within the army and government by relegating them to positions where they could not harm his control. By November of 1926, he began to question Li Zongren's commitment to the revolutionary cause, and began circumventing his authority in favor Zhou Enlai, who was decidedly left-wing. This did not go unnoticed Li, who became disillusioned and resentful. His actions were taken as further evidence of disloyalty, as was the fact that Shanghai was still out of the Republic's hands. Zhou, for his part, smelled opportunity, and fanned the flames of conflict between the two men. On January of 1927, Li was removed from the command of his 110,000 man army, and instead placed in control of a smaller auxillary force sent to secure Nanchang, a city of little strategic importance.
Zhou, now less than 30 and one of the most powerful men on the continent, led a KMT victory outside Shanghai within two weeks of his promotion. They entered the city and soon discovered the harsh new realities of urban warfare. Advances in urban tactics had been made by the Germans during their own civil war, but even those battles had occurred mostly in the countryside and in less densely populated areas. A brick and mortar jungle spanning 20 miles in every direction and including almost 5 million civilians now swallowed the full might of the KMT. The two armies, of about equal size and shape, squared off in this setting, the first of its kind in modern warfare. Fighting took place in the streets, in classrooms, in hallways, in staircases, in abandoned homes. Mines and traps littered the city, picking off soldiers left and right.
Shanghai proved to be a deathtrap for the soldiers of both armies. Escape across the minefields in the north was dangerous. Passing south would take them through miles of scared battlefield ravaged by months of conflict. Thousands drowned trying to flee across the Yangtze river or Lake Taihu. The army that emerged victorious, or at least the one the least beaten, was the KMT. By April 1927, the KMT had captured Wuhan, Nanjing, and Shanghai, but at a great cost. The war had been more costly than expected, and there were calls from within the south to negotiate a peace with the Zhili. Wang was having none of it, and ordered a full on assault on Beijing. Wu Peifu, who had become frustrated with his general's inability to defeat the KMT, took matters into his own hands and took personal command over a Zhili army of 250,000 to stop the advance. The forces on the Korean and Ma borders were removed, and the troops that had been left behind a Beijing were brought along as well. Several miles from Xuzhou, the Zhili's southern advance reached the KMT. The largest battle of the Warlord Period began on June 12th, 1927. The winner, it was feared, would be able to push swiftly into their opponents territory and win the war, unifying China.
The division of China would prove more resiliant than early estimates had expected. Wu beat the KMT at Xuzhou, but his counterattack was extremely cautious, and he did not even reach Shanghai by the time the KMT had moved south and regrouped. The war ground to a stalemate at around the 35th parallel north by the end of the summer, and both sides were under increasing pressure to cut their losses and make peace. Each passing day, Wu grew more paranoid of a Japanese invasion of Manchuria. Spies in Korea warned him of a buildup of troops there and a possible attack. The Japanese had no such plans, but Wu was terrified of an attack and wanted to deal with the KMT as swiftly as possible. Wang, who had begun the war with such vigor, now faced pressure to end it. The KMT had been successful in expanding North, and Beijing now seemed beyond reach. Thus, the Northern Expedition ended in a victory for the Republic of China in what is generally considered the end of the Warlord Period. The ROC, or South China, gained international recognition at the conclusion of the war, though both the North and the South considered themselves the to be the "true" China. The empire, long united, had divided.