Argentinia wasn’t forcibly denazified after the war and was sympathetic to fascism and so a lot of Nazis and fascists fled there to avoid prison or the rope. Mengele lived in buenos Aries until the 90s.
Compare this to francoist spain which always knew it had to walk a tight line because so long as they were ostensibly more on the side of the Allies than the axis they could get away with shit like having their white terror and various other fascist governances. Combine that understanding with a large border with France and axis officers felt it was unsafe to flee to for good reason.