Formed as an organisation to organise the world-wide defence of the Earth from the Martian Guardians in 2034 after the Guardian's first unsuccessful push in 2029, the CDO has protected most of the world for over a century from a war that they knew from the outset that they could not win. They have learnt from the Martian wreckages how to build units that can match even the heaviest bots in battle, but have learnt to mould their units to their own needs rather than simply copying. This has given rise to units that look very similar to early 21st units, but are much larger and more powerful.
After the first invasion in 2008, a great deal of technology was gained from the Martians, including technology that helped keep away global warming and cold fusion power. With this technology, Mankind began spreading out into the Solar System, reaching the Moon by 2013 and Mars by 2019. In 2021, the widescale terraformation of Mars began, and the planet began to warm. This sped up the awakening cycles of the Martians, and in 2028, the second invasion of the Earth began.
After destroying all human settlements on Mars, and spreading a worldwide green fog to cover their operations, the Martians attacked in early 2029, early 2031, and late 2033, doing progressively more and more damage. Tens of millions died from the invasions. However, every invasion was defeated and the many nations began building up their own Martian technologies, though India stayed at the lead.
Hassan Al-Khabir, who had been leading India's air forces since before the colonisation of the Moon had begun, suggested an idea in 2034. He proposed that all nations pool any Martian technology and military units they had and put them under a single organisation, the Cooperative Defence Organisation. Al-Khabir was shortly appointed head of the CDO, and oversaw the building up of Earth's nations' and colonies' military.
The Martian invaded every two years or so, leaving further wreckages to be reverse engineered, but at the cost of millions of human lives. People began to despair and lost faith in their governments. By the '60s, most nations and colonies had become more or less bankrupt as people stopped paying their taxes. The CDO immediately took the initiative to bring all of Mankind under a single banner, and restored faith in the regional governments.
After Al-Khabir ceded power in 2070, there was 41 years of success as one invasion after another was beaten back. Lucas Vaughan, Al-Khabir's successor, continued Al-Khabir's high spending on the military and military research, and construction began on an extensive spacefleet to guard Earth from further invasions and possibly invade Mars itself. Scans of Mars show that humans could safely walk on its surface without any breathing equipment, though they might need some winter clothing to keep themselves warm. In addition, the area around where the Martians emerged from has become extensively fortified with many buildings and units.
After Vaughan ceded power in 2101, Li Xuan takes power and cuts military spending, deeply distrustful of the governing power that the military had. She makes the CDO more democratic, but ultimately also more bureaucratic and corrupt. The Martians manage to build their first permanent base of operations at Antarctica, and the growing fleet has caused them to attempt invasions of the Asteroids and other human colonies. Her undercutting of the military earns her the distrust of Al-Khabir, who still maintains a high position in the CDO Military.
After her fall, four more Supreme Commanders of the CDO followed that continued her policy of undercutting the military and making the government more democratic and bureaucratic. Al-Khabir knows that with such measures the CDO and Mankind will fall.
Military Doctrine Edit
The CDO has a very innovative military doctrine. They don't lean to any particular unit ability, such as firepower or armour, but instead have a wide variety of units that fit almost every possible necessity. Scientists are encouraged to keep an open mind when designing units. The units are thus categorised into three parallel tech trees, that of High-Tech, Tactical and Heavy. The high-tech units primarily use the latest in technologies learned from the Martians or discovered independently, and thus occupy more of a niche role. Tactical and heavy units are however more traditional, though tactical focuses more on firepower while heavy focusses more on armour.