The events of this book led to the setting of Snow Crash.
Assuming that both books are part of an Alternate History. The war of the Big U and the destruction of the Plexus was the beginning of a wave of anarchy that eventually led to the dissolvement of the U.S. government by the turn of the century. Alternatively, it was simply one of the first areas affected by a spark of anarchy that had already begun elsewhere.- Casmir's giant mutant rats were acquired by the government for study, and eventually led to the creation of the Rat Things. By the time of "Snow Crash" the Rat Things were actually enhanced dogs, as canines proved easier to tame (and acquire) than Rodents of Unusual Size. But the original "giant errand rats" used by shady government agencies and organized crime began as Casmir's literal giant rats.
