Fourteen warheads came down across the subcontinent's border ground in 2042; the two governments that owned it stopped existing inside a week. What they left is the Forbidden Zone.
Fourteen warheads in 2042. The radiation never spread evenly, so the Zone is a lace of lethal pockets against ground you can walk all day. Expired clearance codes for the jurisdictions destroyed that year are still worn as decoration. The Heralds of the Storm rose from the ash; the IPFZ has been a conventional power vacuum ever since.