Digidestined Civil War

The Digidestined Civil War, known as the Rebellion by the International Digidestined Alliance was an event taking place immediately after the Third Digital World War. The war pitted the Terrestrial Gennai Army against the International Digidestined Alliance.

Both sides were technically led by Taichi Kamiya. When Tai went to the Digital World in secret to help the Gennai Army, he left Koushiro Izumi to run the Alliance under his name. When Daemon escaped death from the Third Division, he possessed Izzy and commanded the Alliance under Tai's name.

Yonkers Incident
When Tai, Ken Ichijouji, Hikari Kamiya, Takeru Takaishi, Daisuke Motomiya, Michael Washington, Willis Thompson, Miyako Inoue, Iori Hida, Agumon, Wormmon, Gatomon, Patamon,  Veemon, Betamon, Terriermon, Lopmon, Hawkmon, and Armadillomon returned to the human world in Yonkers, New York, they were captured by the International Digidestined Alliance, who believed that they could possibly be members of the Hell Forces in disguise. Mimi Tachikawa attempted to free the group, but was threatened by Jacob McDonald that she would join them in prison. Ken, TK, Davis, Terriermon, Lopmon, Betamon, and Gatomon escaped capture while the rest were taken to Alliances prisons three different parts of the world.

After the Yonkers incident, Ken created The Plan to defeat the Alliance.

Timeskip
During the timeskip in the story, TK and Gatomon destroy an asstortment of Alliance facilities around the world. The meanwhile, Davis stays in New York with Betamon, collecting information from "the Informant" (who is actually Mimi in disguise).

Ken, Terriermon, and Lopmon hid in London gathering information about the locations of the Alliance prisons. Ken is also involved in the Dublin incident and the Battle on the Liffy where he is revealed to have escaped the Alliance capture.

Building the army
Traveling to Paris, Ken recruits many of the European Digidestined into the Gennai Army of Europe. Shortly after, he and the Army repel the Alliance invasion of London in the Battle of Southend-By-The-Sea. He eventually combines the Gennai Army of Europe with the American Free Army and rebelling groups in Asia into the Terretrial Gennai Army.

After building the army, Ken, Davis, and TK free their imprisoned friends from Rocky Mountains Prison, North Sea Prison, and the Gobi Desert Prison and reorganize the Army.

Invasion of Japan
The Terrestrial Gennai Army in America,  prepares to invade Japan from the east, sailing from Seattle. Upon sailing they are met with the Alliance's Navy, led by Jyou Kido. Joe searches for Michael and Mimi, who have gone to the International Peace Park to face off with Jacob McDonald at the Duel at the International Peace Park. Cody, who is leading the aquatic invasion of Japan from the Seattle loses Joe's navy at the Hawaiian Islands and successfully outruns Joe all the way to Tokyo Bay. Davis takes the land army to attack the Executive Council in Tokyo while Michael and Mimi help Cody fight in the Battle of Tokyo Bay.

From Europe, Ken, Yolei and Willis fly across Africa and Asia to Manila, Philippines, where some of Cody's Navy had been relocated. Along the way, they face the Alliance's air force, led by Sora Takenouchi. There, Ken, Yolei and Willis invade Japan from the south, going directly for Highten View Terrace.

From China, TK, Kari, and Tai lead the Terrestial Gennai Army in Asia to invade Japan from the west. TK continues to help Davis fight in the Battle of Tokyo, Kari leads the Army in the Battle of Odaiba, and Tai goes to confront Izzy during the already raging [Battle of Highten View Terrace]].

Battle of Highten View Terrace
In Highten View Terrace, Tai is met by the commander of most of the Alliance's ground forces, Yamato Ishida. After the Terrestrial Gennai Army defeats the Alliance in Tokyo, Tokyo Bay, and Odaiba, they join the Army in Highten View Terrace and defeat Matt's army, Joe's navy, and Sora's air force.

Ken, Tai, TK, Davis, and Kari enter into the real Alliance headquarters and find Izzy commanding from behind a computer. Tentemon is bound and gagged and they find that Izzy is in a similar state to Kari from when she was possessed by Daemon. Daemon leaves Izzy and attacks the Army, only to be defeated by Ken and Wormmon.

After the war
After the war, Ken speakes before the United Nations General Assembly and Michael and Tai speak before the United States Congress, officially disbanding the International Digidestined Alliance. When a UN ambassador asks why the Alliance is not simply continued under UN supervision, Ken argues that true unity does not come from institutions and that rather than uniting the Digidestned, the Alliance divided them.