Complex sentence: Political unrest increased during the late'70s due to the country's severe socioeconomic inequalities that had gone unaddressed by the government; leftist guerrillas began to attack military targets, and other opponents of the regime called for reform.
Split into simpler sentences: Political unrest increased during the late 1970s due to the country's severe socioeconomic inequalities that had gone unaddressed by the government. Leftist guerrillas began to attack military targets, and other opponents of the regime called for reform.