From the Game's Introduction:
The last world war ended almost as soon as the machines began to malfunction. By then, most of the old ideologues were dead - victims of their own fanaticism. Use of humankind's newest weapon, the Quantum Bomb, effected damage on a far subtler level then the cities it flattened.
A wave of subatomic chain-reactions propagated beyond the blast zones. Where the waves met they twisted and strengthened. Around the world, electrical systems began to quietly shut down and vehicles stalled out on the interstate and back-country roads. Eventually, even the lights went out.
Some side effect of the quantum weapons brought the Uncertainty Principle into the macro world. Complex machines and electronics simply stopped working. Even simple machines tended to gum up and break down when they weren't being watched.
Biological and chemical systems seem to be completely unaffected, but the damage had been done; almost overnight the technological world was plunged back into the pre-Industrial era.
Welcome to the Uncertain World.