What passes for strategy in too many businesses, government agencies, and military operations is a toxic mix of wishful thinking and a jumble of incoherent policies. Richard P. Rumelt’s breakthrough concept is that leaders become effective strategists when they focus on challenges rather than goals, pinpointing the of their pivotal challenge—the aspect that is both surmountable and promises the greatest progress—and taking decisive, coherent action to overcome it.  Rumelt defines the essence of the strategist’s skill with vivid storytelling, from how Elon Musk found the crux that propelled the success of SpaceX to how the American military came to grips with the weaknesses of its battle strategy. Musk’s core challenge, for example, was rocket reusability. His intense focus on the soft landing of SpaceX’s rockets enabled them to be used again—radically reducing the cost of putting a pound in orbit. Musk’s strategy was not based on how value is created or how to position SpaceX in its industry. It was a , the mental maneuver that focuses energy on what really made a difference through understanding the crux and creating an effective response that led to breakthrough.