This book provides everything the reader needs to know about the Iraq War, from the Bush administration's decision to invade Iraq, through the U.S. troop surge in 2007, to the rise of the Islamic State. It offers insight into the war through the events, organizations, and people who have had a major impact on the conflict. It also explains the inadvertent consequences of the conflict including worsening regional sectarian divisions, the Arab Spring, the increase in Iranian influence in the Middle East, and the expansion of international terrorism.The book begins with a sweeping overview of the Iraq War that provides context for each of the reference entries that follow. The introductory material also includes detailed essays on the causes and consequences of the war. The bulk of the book consists of more than 120 reference entries on such topics as Saddam Hussein, the battles of Fallujah, and private military contractors such as Blackwater and Halliburton. In addition, the book includes more than a dozen curated and contextualized primary source documents along with a comprehensive chronology and extensive bibliography.