Thanks to Enterprise's most recent block of episodes, we know a lot more about the Eugenics Wars first mentioned in the first series episode "Space Seed." Here's a rundown on what we know about the conflict based on Trek canon (sorry, Greg Cox's pair of novels don't count anymore):
Sometime before 1992 - The Augments are created. The person behind their birth is often quoted as saying, "Superior ability breeds superior ambition." That person was killed by the Augments.
1992 - Augment Khan Noonien Singh assumes control of a quarter of the world, ranging from South East Asia to the Middle East.
1993 - Augments seize power in 40 other nations. The Eugenics Wars formally break out as the Augments fight against the rest of humanity and themselves.
Between 1993 and 1996 - An ancestor of Captain Jonathan Archer led a squad of soldiers in North Africa, protecting a school in a battle related to the Eugenics Wars.
1996 - Eugenics Wars ends. Khan and ninety-six of his followers flee Earth on the Botany Bay, a DY-100 ship regarded as state of the art in the day. The final death toll is pegged at 30 million people. Surviving the war are 1,800 Augment embryos. They are spared and frozen by the Earth governments, who apparently didn't want to deal with the ethical controversy involved in possibly destroying them.
Post-1996 - Genetic engineering is banned by Earth. The 1,800 Augment embryos are all taken to Cold Station 12 for storage.
2134 - Arik Soong steals nineteen embryos from C-12. After further genetic enhancement, he gestates them in incubators.
2144 - While on a mission to gather supplies for the Augments, Arik Soong is captured by Starfleet. He is imprisoned on Earth and apparently refuses to disclose where the Augments were.
And that's what we know up to the Soong trilogy. Now, the question is, knowing all that we do, is it possible to reconsile the Eugenics Wars with real-life? Greg Cox was on to something by making it a guerilla/terror war before both his novels were invalidated by the episodes, but can a covert war account for killing 30 million people? Is it possible for a group of people to seize power over half the world without the general public finding out?