This book examines the motivations behind the interventions of the United States and Russia in civil wars throughout the Middle East and North Africa (MENA).Based on a comprehensive qualitative analysis of case studies in Syria, Libya, Yemen, and Sudan (2011–2024), the book demonstrates how the form and intensity of these great powers’ involvement reflect perceived interests. When interests are high, intervention looks direct and sustained; when interests are moderate, states rely on partners, private military companies, and selective strikes; when interests are low, engagement is mostly diplomatic. The book provides a simple framework, linking historical ties, strategic assets, economic importance, and diplomatic value, which helps readers see why choices that look inconsistent at first in fact follow a pattern. The work’s central claim is clear: Russia’s behavior is best understood as strategic denial, acting primarily to prevent the United States from locking in influence, while Washington is more willing to exploit openings for gains when costs are acceptable. Utilizing theory with concrete evidence from each case, the book offers an approachable guide to how great powers decide whether, when, and how to intervene, and how their methods change once a rival moves first.This book will be of much interest to students of security studies, foreign policy, Middle Eastern politics, and international relations.