Interplanetary War

The Interplanetary War was a large war among the United Nations, the neo-communist Koslovics, led by Vladimir Koslov; the fascist Frieden, backed by corporations of the Unified German Republic; and a number of other national governments that was waged throughout the Sol system. It was the culmination of four prior years of war, which included the Jovian Moons Campaign, the Rain Forest Wars, and the Argyre Planitia Campaign.

Background
As overpopulation and unrest mounted on Earth, a number of new political movements were formed, including the Koslovics and the Jovian Frieden movement. The Frieden attacked United Nations colonial advisers on Io, one of the moons of Jupiter, and UN-sponsored military forces began a pattern of massive buildups which culminated with the Interplanetary War. After a successful UN Marine attack on Mars, recruitment drives and propaganda tactics strongly bolstered the military forces of the newly formed United Nations Space Command.

2160
Secessionist forces, mostly Frieden rebels, attack UN colonial advisers on Jupiter's moon Io. This leads to several months of fierce fighting between UN forces and Frieden rebels on the Jovian moons. Though it is not the first such engagement, it is one of the bloodiest, leading other Earth governments to fight proxy wars off-planet and throughout the Solar system. This soon leads to the Rain Forest Wars.
 * Jovian Moons Campaign

2162
Heavy armed conflict among UN, Koslovic, and Frieden forces erupts in the tropical rain forests of South America. These clashes result from ideological differences and the wish to control important areas of Earth. As the conflict rages, even more fighting sparks on moons and other planets in the Sol System.
 * Rain Forest Wars

Friedenists and Neo-Friedenists clash over internal differences on Luna.
 * Battle of Delambre

2163
The UN launch various lightning strikes against Koslovic forces in the Argyre Planitia on Mars. This is the first extra-terrestrial deployment of Marines by the UN. This is later used as a military doctrine in all situations off-planet, and marks the start of the UNSC.
 * Argyre Planitia Campaign

2164
Recruitment drives and propaganda tactics strongly bolster UN forces. UN forces defeat Koslovic and Frieden forces on Earth and then begin a systematic and dedicated drive to crush their remnants on the various planets they hold throughout the system. Ultimately, Frieden and Koslovic forces are defeated in the face of a massive, unified, inspired, and very powerful UN military, now known as the United Nations Space Command.

2170
2170 marks the end of the Interplanetary War with the Callisto Treaty, with the Koslovics and Frieden commanders surrendering to the UNSC. 2170 also sees the formation of the Unified Earth Government in the wake of the conflicts of the 2160s. After the conflict, the UNSC are forced to deal with a less obvious but equally serious threat: overpopulation and a massive military that has no enemy to fight. In the post-war period, there are massive population surges and the overpopulation that, coupled with the destruction and famine bred by the Rain Forest Wars, threaten to destabilize the interplanetary economy.

List of appearances

 * Halo: The Cole Protocol
 * Halo: Evolutions - Essential Tales of the Halo Universe
 * The Impossible Life and the Possible Death of Preston J. Cole