The purpose of this research is to validate the systems model of insurgency and counterinsurgency by examining two case studies in counterinsurgency; the Emergency in Malaya from 1948-1960 and the ongoing war in El Salvador. One of these case studies proved to be a success, and one thus far has proved to be a failure. The paper's proposition is that successful counterinsurgency, as in Malaya, requires that the government view the insurgency as a system and attack each of the insurgency's components (inputs, conversion process, and outputs). Conversely, unsuccessful cases of counterinsurgency, such is in El Salvador, are those in which the government focuses exclusively on outputs. This study will attempt to validate this proposition by analyzing the conflicts in Malaya and El Salvador in similar terms using the systems model. Insurgency, Counterinsurgency, El Salvador, Malaya, Revolutionary War.