Árbenz decided to arm the civilian population to defend the capital; this plan failed, as an insufficient number of people volunteered. At this point, Colonel Carlos Enrique Díaz de León, the chief of staff of the Guatemalan army, reneged on his support for the president and began plotting to overthrow Árbenz with the assistance of other senior army officers. They informed Peurifoy of this plan, asking him to stop the hostilities in return for Árbenz's resignation. On June 27, 1954, Árbenz met with Díaz, and informed him that he was resigning. Historian Hugo Jiménez wrote that Castillo Armas's invasion did not pose a significant direct threat to Árbenz; rather, the coup led by Diaz and the Guatemalan army was the critical factor in his overthrow.