The war quickly escalated from a regional war to a worldwide war. The United Pacific Aligned succeeded in taking out the United States of JBR (partially) and Union of Midway in the early stage while the Caribbean Treaty Organization weakened the Deltoran Republic. UPAC decisively attacked countries within South America and attempting to use the resources of their captured states to fend off the Sunshiner troops. The Prussian Empire was one of the primary threats to UPACer success in capturing all of the South American continent due to frequent Prussian raids. UPAC could not directly attack the Prussian Empire due to the Empire's strong ties with other European nations so it decided to attack the JBRican States, Midway, and the Pacific Empire. The Pacific Empire was forced to cede two of its colonies as per terms by UPACer demands. The colonies ceded were the United Prefectures of Japan and the Republic of Oceania. However, these newly created nations supported the Empire and joined the war. The Pacific Empire soon faced threats from North Korea and the increasingly aggressive colonies of China and Vietnam. The JBRican States was able to liberate itself from UPAC control while the Union of Midway continued to be known as the Democratic People's Republic of Midway. In early June, UPAC began experiencing internal revolts in both its possessions and member states. Despite success in the Sunshiner side, the Soviet Union of Socialist Republics emerged as a new threat and even overwhelmed Sunshiner naval troops in a single battle. Then, on June 14, the United Pacific Aligned Coalition offered to be surrendered and formally surrendered the same day with the Treaty of Lima. On June 15, the war came to an end when the Caribbean Treaty Organization surrendered with the Havana Treaty and the Arab states that supported CTO signed an armistice with the Prussian Empire.
May 19: The JBRican states of Diego Commonwealth, Mexicali, and Imperial are captured by UPAC. This prompts the Californian Union to withdraw troops in the American Theater to return to the United States of JBR and Central Kingdom to defend from the invading UPAC forces.
May 21:The Pacific Empire, Republic of Oceania and United Prefectures of Japan issues a joint declaration of war on Peru, Chile, and North Korea pledging to liberate the United States of JBR and Union of Midway.
May 21:People's Republic of China declares war on the Pacific Empire, Republic of Oceania and United Prefectures of Japan in support of North Korea.
June 9: A nuclear bomb over Quarthe is intercepted by the Prussian ASDI system, plunging Europe into a crisis. Von Schliefen organizes an emergency meeting with other European leaders, set to finish by the next day.
June 10: After a night of talks, the European War Coalition forms and declares war as a single entity against UPAC.
The Great Pacific War has become a major reference in Sunshiner nations. Within the Sunshine Treaty Organization Pact, many countries have adopted a remembrance day on June 15 commonly known as the "Victory Day". Popular culture and media have spawned various events referring to the war. In the UPACer side, many countries have similarly adopted a "Victory Day" under the name "Day of Peace". Monuments and memorials have been erected since then, including the Great War Monument in JBR City and the Nakazawa Shrine in Aldebaran.