This book is about International Relations Theory. It argues that Neo-classical Realism gives a better explanation of world politics than the other themes of Realism. The book attempts to demonstrate this argument in the case Hormuz crisis 2011. Therefore, it addresses the real dynamics in which have led Iran to threat to close Hormuz. This includes the systemic constrains that are produced by the international system and the politics of great power, and the domestic politics inside the country, the domestic nuclear debate. Hopfully, you will enjoy reading it, as I enjoyed writing it.