Complex sentence: Mexicans were beginning to interpret the European battle between the communists and fascists, especially the Spanish Civil War, through their unique revolutionary lens, and whether Mexico would side with the United States was unclear during Lázaro Cárdenas' rule, as he remained neutral.
Split into simpler sentences: Mexicans were beginning to interpret the European battle between the communists and fascists, especially the Spanish Civil War, through their unique revolutionary lens. Whether Mexico would side with the United States was unclear during Lázaro Cárdenas' rule, as he remained neutral.