very mild WW3. Earth is a wasteland where almost all animals died from radiation long ago and anything that survived it is an object of worship. Survivors need to go through periodic checkups, those affected by radiation are labeled off as "chickenheads". People are emigrating to desert Mars - which is an even worse wasteland, where things are so bad that even the Robots are trying to escape back to Earth, such a Robot has to kill his former master and then pose as his former master. (the whole plot is about finding these Robots)

The culture of the survivors is based on this worship of what remained of the animal kingdom, as seen in the test that they administer to check if you are a robot or not.

Especially amusing: the Robots in the book are hallucinating - (these hallucinations are called 'false memories'), just as these large language models of ours...