Dai Hoa Unification War

The Dai Hoa Unification War (チエン ツラヲ ノヲ ニアツヽ), also known as the First Hoaian War, was a war between the Union of Dai Hoa (with the support of Arshavat) and the Song Republic (with the support of the Three Powers Alliance, principally from Chisei). The war began on 15 June 1957 when Dai Hoa invaded the Song Republic following clashes along the border and unsurrections in both the north and south. The war ended unofficially on 2 May 1960, when the Hoaian forces secured the former Songese capital Hai Phuong. The Songese regime fled to Dep Dao, where they remained until the Second Hoa War in 1997.

During the Second Escar-Varunan War, Arshavat invaded the Yamataian colony of Yamataian Nanyōkuni. Seeking to oppose Arshavati expansion, the Escaric Allies and Yamatai signed the Treaty of Senbonzakura, an armistice between both belligerents, in order to jointly prevent Yamataian Nanyōkuni from falling entirely into Arshavati hands. With the Treaty of Hai Phuong on 17 January 1945, Nanyōkuni was partitioned between Arshavati and Yamataian control based on the front lines at the moment of ceasefire. On 1 February 1945, the Arshavati-occupied area declared independence from Yamatai as the Union of Dai Hoa, while the southern area remained under Allied-occupied Yamataian colonial rule. The Song Republic was later founded on 20 June 1947. The governments of the two new states both claimed to be the sole legitimate government of all of Nanyōkuni.

Tensions remained high between both states for the first decade of their existence, reflecting the developing Escaric Divide. Both states sponsored insurgencies within the other, and border clashes were common to the point that in 1954, the newly-formed Ordic League declared a demilitarised zone be formed between on the border between Dai Hoa and the Song Republic. However, this did not stop the border clashes, which gradually worsened especially in the central highlands.

On 15 June 1957, forces of the People's Army of Dai Hoa crossed the DMZ and advanced into the Song Republic. The Songese forces were initially pushed back, but fighting soon stabilised along a front line in the northern Songese provinces. Though the Western Escaric states denounced the Hoaian invasion of the Song Republic, they initially did not carry out overt actions in support of the Song Republic out of fear of an open war breaking out with Arshavat, East Kuiju, and Liang. However, heavy materiel support and funding was given to the Songese war effort by the newly-formed Chisei-led Three Powers Alliance, with a similar arrangement between Dai Hoa and Arshavat.

A particularly devastating Hoaian offensive in November 1957 using new tanks and jet aircraft from Arshavat enabled Dai Hoa to push through the Songese lines, advancing deep into Songese territory. Alarmed by this turn of events, the Three Powers Alliance joined the war on 17 December 1957, ostensibly to defend their mutual ally the Song Republic. The Chiseian Royal Navy deployed a force into the Gulf of Quanhco and troops from Chisei, Yeongseon, and Yamatai were sent to join the fighting directly. The Dai Hoa forces were pushed northwards and beyond the DMZ by the Spring Offensive, with the front line soon closing in on the northern provinces. Concerned for its security, Arshavat deployed over 800,000 "volunteer" troops to Dai Hoa in May 1958 to bolster the Hoaian defence, prompting a retreat by the Alliance and Songese forces.

By September 1958, the fighting again stabilised along the original border, devolving into trench warfare due to the thick jungle terrain of central Nanyōkuni preventing large-scale armoured pushes. Seeking to break the deadlock, on 23 September the Alliance forces carried out an amphibious invasion of Dai Hoa, landing at Yamethin on the Hoaian coast and enveloping off many People's Army and Arshavati troops. Meanwhile, an uncharacteristically aggressive naval quarantine of the area by the Chiseian Royal Navy affected Arshavati supply lines, enabling the southern forces to push into Dai Hoa again. By November the Alliance forces were again on the verge of pushing deeper into Dai Hoa again, prompting Arshavat to resort to nuclear weapons.

The only usage of nuclear weapons during wartime in history, Arshavat deployed a total of three nuclear weapons during the Dai Hoa Unification War. On 2 December 1958, the first bomb was dropped tactically on Thaketa to destroy the Allied front line, and the second was dropped roughly simultaneously against the Alliance offensive at Dagon. The third bomb was dropped strategically on Yamethin on 5 December, which the Allies were using as a stronghold for their amphibious forces. A fourth bomb was to be deployed on Hai Phuong, but the bomber carrying it was shot down by Songese fighters and the bomb recovered in secret by Yamataian forces.

Shortly after the devastating usage of nuclear weapons by Arshavat, the Three Powers Alliance forces immediately began to withdraw from the war to avoid further aggravating Arshavat. Large amounts of materiel were intentionally left behind for the Song Republic's use, though the ground troops were entirely recalled. By February 1959, the last Alliance troops had left Nanyo. At the same time, Hoaian leader Nguyễn Tất Thành was horrified by the outcome of the nuclear attack, the destructiveness and collateral damage of which was not clearly explained to the Hoaians. Nguyen subsequently formally requested that Arshavat withdraw its forces from Dai Hoa in March, slowing the offensive against the Song Republic and beginning the roots of the Hoa-Arshavati Split.

Despite the removal of Arshavati support, Hoaian forces quickly began to push into the Song Republic, though tenacious resistance in the southern coastal provinces again stalled the front lines for much of 1959. After July 1959, the Songese government began to seek alternative options due to the increasingly unwinnable war situation. From August, they began evacuating key government and military functions to the island of Dep Dao, also moving much of their remaining wealth and historical valuables. In early 1960, Songese military forces also began to retreat to Dep Dao, abandoning the mainland. On 2 May 1960, the Hoaian forces captured Hai Phuong, and Dai Hoa declared an end to the war shortly after.