This book will answer the key research question of which characteristics (changing or enduring) of the Syrian War caused Turkey and Russia to oscillate between the extremes of war and alliance. By focusing on these characteristics in Syria, commonly accepted as a proxy war but with subtle changes to the definition due to its context, this book shows how the changing character of war influences state behaviors and relations both between and among them. Addressing the underlying question of what makes states cooperate while carrying on and/or being forced to accommodate diverging strategic ends, conditioned by unbalanced military power and laden with contentious agendas, uncovers the embedded controversies of the process that facilitates this oscillation. Finally, to reveal the broader implications, highlight the relevance, and to make a contribution to the literature based on the research, this study addresses the overarching question of how proxy wars alter interstate relations and relations within alliances.