This week on Uncommon Knowledge, military historian Max Boot discusses current events in Syria, Iran, and his recent book Invisible Armies: An Epic History of Guerrilla Warfare from Ancient Times to Present. Boot explains how guerrilla warfare has been, and still is, the most common form of conflict even today, as seen in Syria and Afghanistan. Since conventional tactics do not work for unconventional armies, Boot offers lessons to be learned and applied to today's battles. Boot further argues that now it is more important than ever to understand the history and operation of insurgent forces.