Since ww2, many Nazis and other Fascists fled to Argentina rather than stand trial for War Crimes. Some of them included Wernher Von Braun, who helped design the infamous V1 flying bomb that was feared and despised by many Russian and French soldiers. Others included the Scion of the Krupp family, who brought their entire fortune to Argentina and set up shop there.
Since the Second World War ended, Latin America became polarized with Peron's corporatist dictatorship gaining support in Chile and Paraguay. Brazil (US/Russian backed) opposed Argentina and got together with Venezuela and Bolivia to form the Bolivarian alliance. The Stage was set for a showdown.
On March 23, 1957, 6 Argentinian Mark 5 Fighter/bombers launched a preemptive attack on a Brazilian outpost, lighting an overflowing powder keg of tensions.
a few days later, Brazilian tanks crossed the Paraguayan borders and closed in on Asuncion. But Paraguayan forces prepared for street-to-street fighting, with a battle that lasted a month before Asuncion fell.