Country Lead: Rex W. Douglass The Vietnam War is one of the most important sources of US counterinsurgency doctrine and lessons. The micro-level econometric methods available today allow researchers to revisit this case to test these lessons as well as more recent hypotheses on insurgency mostly having to do with conditions favoring the flow of information about insurgents from civilians to COIN intelligence. Many analysts argue that the fundamental dynamics of counterterrorism and counterinsurgency have changed in the last 20 years due to various geopolitical factors—the end of the Cold War, rise of transnational Islamist activism, and others—and technological factors—cell phones, the internet. The secular backdrop and Cold War time period of the Vietnam War is helpful for identifying whether hypothesized explanations of terrorism and insurgency are conditional on various intervening geopolitical and technological factors of the current period. Previously-untapped U.S. government data collected during the Vietnam War make it possible to study the relationships between governance, development, and terrorism in Vietnam using the same econometric techniques we are applying in Iraq, Afghanistan, and the Philippines. ESOC research on Vietnam has focused on the role of civilians in the production of violence and whether reconstruction activities under the Civil Operations and Rural Development Support (CORDS) program worked to reduce insurgent activity and boost popular support for the government. ESOC data on Vietnam include data on violence, the pacification status of villages, and measures of development and governance contained in the Hamlet Evaluation System (HES; similar to the SIGACT-III data for Iraq). An advantage of Vietnam relative to the current conflicts is that researchers can move beyond econometric analysis to detailed case studies. Records of unit positions and activities, violent events, rebel defections, and civilian targeting by both sides will be combined with qualitative accounts gathered from captured Viet Cong documents and participant interviews.