Asymmetric guerrilla war—insurgencies, internal wars, and other small-scale contingencies (SSCs)—are the most pervasive and likely type of conflict in the post-Cold War era. It is almost certain that the United States will become involved directly or indirectly in some of these conflicts. Yet, there appears to be little or no recognition and application of the strategic-level lessons of the Vietnam War and the hundreds of other smaller conflicts that have taken place over the past several years. The author draws from the lessons of the recent past to better prepare today's civilian and military leaders to meet the unconventional and asymmetric warfare challenges that face the United States and the rest of the international community. This country is in a new global security environment that involves the integration of free markets, technologies, and countries to a degree never before witnessed. It is not easy to understand and respond to the many smaller threats—and benefits—that stem from global integration. Yet, as the country that benefits most from global integration, the United States has a pressing national interest in maintaining and enhancing the new order. By coming to grips analytically with the most salient strategic lessons or rules that dominate contemporary SSCs, political and military leaders can maximize opportunities in the current and future chaos.