Paper Bridge War

The Paper Bridge War (紙橋戰爭/La guerre du pont de papier) also known as the Sino-French War is a war between the France and Qing China but mainly fought in the Qing tributary of Nguyễn Vietnam, the Paper Bridge War was a blow to French dominance in the region after losing the war to China.

Prelude
From the late 18th century, France had interests in North Vietnam when a french priest recruited french volunteers to fight for Nguyễn Ánh to establish the Nguyễn Dynasty. This was in an attempt to give previllage for french and the Roman Catholic Church. France officially started it's colonial campaign in 1858 and annexed many southern provinces to create Cochinchina in 1862. Later french explorers travelled up the Red River into Yunnan hoping to find a profitable route to China bypassing the Chinese trading ports. This failed as the Black Flag Army which was a group of bandits would force travellers to pay "taxes" on the river. In 1873, a small French forces started an expedition into Vietnam but were defeated by the Black Flag Army.

Henri Rivière's expedition
In 1881, Henri Rivières was tasked to investigate complaints by locals on french merchant activities in the country. Defying orders, Henri Rivières stormed the citadel of Hanoi in April of 1882. Although it was eventually returned to the Vietnamese, it alarmed both Vietnam and China. Hoping to get ride of Rivières' forces i Vietnam, the government asked the help of the Black Flags as the government army was too weak. In addition, Vietnam also asked the help of China which in turn supplied the Black Flags indirectly opposing the French.

The Qing court was alarmed by this and decided to occupy several border towns along the Chinese-Vietnam border. The french minister to China was also alarmed by this move and started negotiations in November and December to split Vietnam between Chinese and French sphere of influence. Rivières, who was disgusted by the french minister's deal with China decided to take the problem to his own hand by occupying Hanoi then Nam Dinh. The Black Flags then attacked Hanoi but were defeated at the Battle of Gia Cuc. The battle unofficially started a skirmish between Vietnam and Rivières' expedition.

French Intervention
With Jules Ferry taking over as the French Prime Minister who favoured more colonial expansion. The French government in Indochina, primarily the naval command of the region, escalated border skirmishes and expeditions into a full scale undeclared war with the storming of Huế by French naval forces.

Chinese Intervention
To which the liberalizing and modernizing China took as a serious threat. The Emperors most liberal supporters saw the war as a chance to prove their new might and to supplant their sphere of influence in Northern Vietnam, while the more moderate members of court felt that while the army was not ready, and the navy even more lacking, that any further reduction in their borders influence and they might risk the French intervening in China itself, much as the British had in earlier decades. With this coalition combined, and the already hawkish Emperor, a larger conflict could not be avoided. Sending both the Nanyang Fleet and Guangdong Fleet to base out of Canton with striking bases in Sanya and Haiphong, early naval exchanges were mostly tests of mettle, as so far the French, seeing the more modernized Chinese, had waited for naval reinforcements from the Indian Squadron.

Sino-French War
True combat began in December with the Sơn Tây campaign, in which the French pressed upwards towards Sơn Tây, seeking a decisive victory. Moving quickly, due to the time it would take for modernized land elements of the Qing army to arrive, Amédée Courbet was able to push on and take the city from the Black Flags through a gritty battle. Though successful, and even able to deal a hard blow to the Vietnamese due to their reluctance to retreat, losses were higher than hoped for.

In a twist of fate, Amédée Courbet would be killed in a reprisal attack by Black Flag guerrillas, sniping the admiral off his horse while inspected some of his troops. With the loss of their leader, French forces were paralyzed for a time. With 1884 beginning, Charles-Théodore Millot assumed command of the French forces in Vietnam, immediately moving to take Bac Ninh.

His force remained at only 7,000 troops, as reinforcements from Algeria and the Foreign Legion intended for Tonkin had been diverted towards an ill-fated Borneo campaign. The march on Bac Ninh was a success, though due to the Frenchmen’s low numbers, their success was far more limited, unable to smash the Black Flags new recruits in the field, leading a siege of the entrenched city, lasting well into April. Though capture was possible, the time it took to do such and the lack of reinforcements essentially left the French unable to do further campaigns for 2 months, while they awaited replacements for their losses. The Emperor, reassured that the war could be turned, committed to fighting in full, as Chinese forces finally arrived in Vietnam, under the command of Li Hongzhang, who had shown much promise and gained much favor for putting down the Taiping, and his assistance in the self strengthening movement.

Invasion of Taiwan
French operations initially were limited, as the Expeditions forces got to the coast, embarking on the combined Asiatic Squadron and attempting to commit to an invasion of Taiwan in order to force a peace. This would be the main ground for the war. The battle of Penghu would occur as the Asiatic Squadron would encounter the combined Chinese fleet outside of Taiwan, as after a brief battle outside of Qimei, the Qing fleet would be forced back, but not without significant damage on both sides. The French would now make a major misstep, landing the expeditions forces on Taiwan before sending the forces in need of repair to Hong Kong in order to receive said repairs.

French forces under Jacques Duchesne fought against Qing forces on Formosa, capturing Tainan City and, due to lack of supplies, had to stand and fortify. The Green Banner army, deployed to Taipei, marched southwards, quickly laying siege to the city. French naval assets, divided as they were, made easy prey for the Qing fleet, repaired rapidly in Xiamen and Quanzhou.

Result
With the complete failure of operations into China proper and the general unpopularity of the war in mainland France together with the Black Flag attacks scaling to ever greater amounts in 1884, the Treaty of Canton would be signed by the opposing sides. The treaty placed Tonkin under Chinese protectorate along with the French paying a major indemnity. This war served to collapse the Republican government of France to political irrelevance for nearly 2 decades, along with proving Chinese capabilities to fight off Western powers, even though it took significant resources. This also solidified the hold of modernists within China, resulting in further modernization of the whole army. In coming months, Liu Yongfu would effectively coup the Vietnamese government, establishing a staunchly pro-Chinese and anti-French government, while starting to use some nationalist ideas.