John Lewis Gaddis' On Grand Strategy deals with a complex subject but in understandable and relatable terms. Gaddis, along with several other distinguished academics, teaches the "Studies in Grand Strategy" seminar at Yale University. This is a class with competitive admittance that often includes a mixture of undergraduates, graduate students, and some military professionals. This book is a distillation of that seminar.

At the heart of this book are two interrelated themes—the conceptualization and execution of "grand strategy" and the type of "genius" leadership necessary to successfully prosecute strategy. Throughout the book, Gaddis (borrowing from Isiah Berlin) sketches a historical narrative that features "hedgehogs" and "foxes." The former, like Xerxes or Vladimir Lenin, were individuals who had one holistic theory about how the world worked and sought to bend reality to that theoretical vision. Foxes, on the other hand, like Queen Elizabeth I, were subtle thinkers who saw the complexities in everyday life and sought to balance "contradictions" in their mind simultaneously.

Of course, this is mostly a false dichotomy, as even Berlin once quipped that his bifurcation of intellectuals into "hedgehogs" and "foxes" was primarily an oversimplification and attempt at some humor in an early published essay. Still, however, there is something to be said about complex thinkers like Abraham Lincoln who were able to perceive in the world all of its numerous contradictions and, as FDR once remarked, not allow his left hand to know what his right hand is doing. Their ability to execute grand strategy—the connection of nearly "infinite ends" with "finite means"—surpassed that of the "hedgehogs" like King Philip II who sought to closely tie Spanish grand strategy under his reign with his omnipresent Creator who would "provide the means" to achieve unlimited, unknowable ends. Lincoln successfully navigated the American Civil War and achieved reunion. Philip II mostly kept the Spanish Empire intact, but saw Spanish fortunes wane vis-a-vis Elizabethan England after 1588.

There is much to like about this volume, and as the quip by John Nagl says on the cover: "A book that should be read by every American leader or would-be leader." The emphasis on always aligning desired outcomes to the available means to achieve them is something that every responsible leader should consider, regardless of their respective role within an organization or nation.