Castillo Armas faced significant internal resistance, which was blamed on communist agitation. The government, plagued by corruption and soaring debt, became dependent on aid from the US. In 1957 Castillo Armas was assassinated by a presidential guard with leftist sympathies. He was the first of a series of authoritarian rulers in Guatemala who were close allies of the US. His reversal of the reforms of his predecessors sparked a series of leftist insurgencies in the country after his death, culminating in the Guatemalan Civil War of 1960 to 1996.