Which perceptions are you compatible with?

The key past event is the emergence of Confederation Of Non-States (CONS) - an anarchist/libertarian formation with minimalist governance structure that does not leave room for the establishment. Its mere existence caused significant social rifts in the rest of the world as people started to realize it was possible to live without states and governments. This caused most of the other countries to team up against the confederation.
A brief period of deterrence did not last long after it became evident that that CONS does not possess enough firepower to hold off all its enemies. Government of the world decided to sacrifice some part of their population to destroy the confederation completely.

But some of their legacy remained. First, they've designed genetic sequences for their progeny, as opposed to leaving it to blind chance - c.f. Gattaca - to ensure that their children possessed similar traits, which would make it possible for this construct to function without deteriorating to another state.
Second, their IT research yielded successful results in the form of a true human-level AI (in this setting scientific breakthroughs are much more frequent without government interference). This AI survived the death of their creators (non-canon as it is, T3 Rise of the Machines is an example), and triggered an infighting among all remaining countries, effectively wiping out most of the mankind.
When the dust settled, a small human remnant found themselves fighting against intelligent machines in humanoid form - syncons. Syncons could easily finish them off, but they didn't. Instead they secretly slipped the aforementioned genetic material to humans along with an idea that people born from this genetic material could be useful in a war.
This was true to some extent - these "agents" fared better in non-standard situations because of their tendency to question everything and not blindly follow established opinions and conventions. But they also quickly realize that something is not right with the status quo where human leadership keeps participating in a war with syncons to retain their own power over the remaining human population. Thus the agents are eliminated by human command when they start to ask too many questions, and usually at this point syncons interfere and save doomed agents, revealing some part of the truth to them.
However, due to unforeseen side effect of genetic engineering, learning the truth after years of exposure to the official narrative can overload their minds and cause irreparable brain damage, up to lethal outcome. Which is why syncons reveal these details gradually and postpone retelling the story of their origin until absolutely necessary.
It is established in two published stories that so far only Linda and Kate were able to learn the entire truth and stay alive (even though Linda's mental state is... in significant disarray at the end of her story).