|This article covers a war or battle
As the 20th Century began, Japan was one of the foremost powers in the Asia-Pacific region. Many politicians sought to emulate many of the ideas that Emperor Meji had allowed in Japan, with Communalism being one of the most heavily studied at Japanese Universities.
After the Red Revolution in the 1870's/80's, Communalist teachings were banned under the leadership of Meji, who started jailing any Communalist sympathizers. But that only infuriated many leaders, who orchestrated a revolt with armed peasants and Communalist influenced portions of the Imperial Army. The Japanese War officially started as Imperial Japanese troops confronted the Japanese Red Army outside of the city of Sendai.
Western Involvement (1911-1919)
The Western Powers, worried for their Japanese ally, began covertly supporting the Imperial Army against the well-armed and German backed Red Army.
The British and Americans eventually sent in troops to combat the Japanese, not wanting another nation to fall to the Red menace. This was the first time that tanks and aircraft were deployed in warfare, albeit in a somewhat limited capacity for the former.
But due to the Chinese renting out land to the British and Americans, small airfields were built to support early aircraft that were built for armed combat.
American, Chinese, British and Imperial Japanese troops fought in numerous battles for control as the North Japanese marched further south, eventually culminating in the Battle of Tokyo in 1914, forcing the Emperor to flee to mainland Japanese Manchuria.
Australian General John Monash used the newly developed tanks to his advantage, alongside huge naval bombardments from the Royal Navy, and liberal usage of open warfare and proto-Blyskawica (OTL Blitzkreig) tactics, Monash and his Japanese allies successfully liberated portions of Southern Japan during the Great March Northwards in 1915-1917.
American General John J. Pershing wished for the usage of chemical weapons on North Japanese cities and industrial zones, but then-President William H. Taft fired Pershing after his numerous pleas to the President.
At the War's end, both Japanese forces had reached the middle of the Home Islands, with the control of No Man's Land (so-called due to the huge amounts of artillery fire reducing small villages and towns to rubble) fluctuating between North and South until the German government stepped in and issued a ceasefire.
On December 22nd, 1919, the Japanese War ended after nearly a decade of fighting in Japan and Mainland Asia. The German Worker's Republic mediated the ceasefire between the two nations in 1920.