The Demilitarized Zone of Comodoro Rivadavia was established after the Soviet-Argentine War of 1991, the declining Argentine Junta - which had long laid claim to the southern atlantic islands - invaded the Soviet All-Union Territory of Islas dos Estados over a disagreement in interpretation of the
1892 treaty defining the 99-years lease of the island. Effectively Argentina hoped to seize the loosely defined and under-staffed All-Union territory before any of the soviet successor state could get internationally-recognised sovereignty to it. Instead of precipitating the collapse of the USSR, Gorbachev succesfully claimed the rally-around-the-flag effect, and after an improbable trip of the Admiral Kuznetsov and a much-criticised aerial and submarine bombing campaign over Patagonian infrastructures culminating in the occupation of Tierra Del Fuego, the Argentine Junta was forced to the negociation table, where Staten island was ceded to the USSR to perpetuity and Patagonia was Demilitarized, the soviet victory is often credited as a much needed lifeline for the credibility of the soviet institutions and army (even if declassified documents revealed that British logistical support had been crucial to the soviet war effort) that allowed Gorbachev, and his successor Nazarbeyev to partially reform the USSR and extend its life expectancy even as the lesser SSRs were seceding.
The Comodoro Rivadavia DMZ was established over the territory of the
Comodoro Rivadavia Military Zone, that zone had been created at the start of ww2 over the strategic importance of Patagonia's mineral ressources, its proximity with three powerful rivals and as a way to control the region's powerful worker and anarchist movement, which had been emboldened during and after the russian civil war by the escape of russian political prisonners and later the proximity to the USSR; it was quickly extended to encompass the whole of Santa Cruz and Tierra del fuego territories. Through its 50 years long existence, the Military Zone grew from 40,000 to over 700,000 inhabitants, and its capital Comodoro Rivadavia went from an insgnificant town to a city of over 200,000, becoming the second largest city below 40°S after Christchurch.
Staten Island would be invaded once again by Argentina in 2025 during the Environmental Revolution that overthrew the remant of the U.S.S.R.
A quick map I did in a few hours for the
MOTF 265