The CARVER matrix was developed by the United States Army Special Forces during the Vietnam War. CARVER is an acronym that stands for Criticality, Accessibility, Recuperability, Vulnerability, Effect and Recognizability and is a system to identify and rank specific targets so that attack resources can be efficiently used. CARVER was developed in World War II by the OSS for the French field agents as a simple, uniformly and somewhat quantifiable means of selecting targets for possible interdiction. CARVER can be used from an offensive (what to attack) or defensive (what to protect) perspective.