U.S. Marines in Irregular Warfare: Training and Education is a brief history that recounts how the U.S. Marine Corps adapted to fight the Global War on Terrorism during 2000-10. The Marine Corps has a long history of fighting irregular wars, including the Banana Wars in Central America during the 1920s and the Vietnam War during the 1960s. To battle the insurgencies in Iraq and Afghanistan, the Corps drew upon this experience while also implementing new plans and programs to better prepare Marines to carry out counterinsurgency operations. The Marine Corps updated the curriculum at the Command and Staff College and transformed the annual Combined Arms Exercise into Exercise Mojave Viper: an immersive training program that simulated the urban environments in which Marines would be operating in Southwest Asia. Most importantly, Marines adjusted in the field, as battalion and company commanders drew on their basic training and education to devise innovative tactics to better combat the new threats they now faced. ?us, as this story shows, the Marine Corps did not undergo a radical transformation to fight in Iraq and Afghanistan, but instead drew on principles that had defined it as a warfighting organization throughout most of its history. Keywords: United States Marine Corps; United States Marines; U.S. Marine Corps; U.S. Marines; Marines; Marine Corps; Global War on Terrorism; global war on terrorism; irregular warfare; military strategy; counterinsurgency; combat; iraq war; Iraq War; Afghanistan; military education; soldier training; combat training and tactics; Southwest Asia