Throughout history, the world has witnessed enemies putting aside their differences to unite for reasons that often defy logic. Whether motivated by survival, a common threat, or the lure of opportunity, these alliances reveal just how unpredictable human nature—and global politics—can be. From fierce wartime adversaries to bitter corporate rivals, the stories of rivals-turned-allies are as fascinating as they are surprising. In the following examples, you’ll discover how necessity, desperation, or even sheer irony have brought together some of the world’s most unlikely partners.