I don't think I learned anything about strategy. The book does seem to be an outstanding example of hindsight bias (or maybe survivorship bias?): Gaddis's exemplars of good strategy (Octavian, Elizabeth I, Franklin Roosevelt and a few others) all seem to have muddled through challenges/wars as best they could and ultimately prevailed - otherwise, Gaddis would not have picked them. The exemplars of flawed strategies (Xerxes, Philip I, Napoleon) were also exceptionally successful people who did their best in wars, until they lost in the end, which the book argues was due to their flawed strategies. But correlation is not causation. When Queen Elizabeth balked at making certain decisions, Gaddis calls it clever "dithering" that ultimately achieved a larger purpose; when Napoleon did the same thing, Gaddis calls it indecision or paralysis. I didn't see any real, qualitative difference between the two leaders - just luck and hindsight.

Anyway, the book is still an enjoyable skip through history, from ancient Greece through World War II. It lucidly illustrates Isaiah Berlin's distinction between hedgehogs (leaders with one big idea that organizes all their actions no matter what) and foxes (leaders who juggle or switch between ideas as the the circumstances change). Gaddis says good strategy means doing both, or in his words, "a fox with a compass." That seems like an obvious cop-out, but okay. But how are we to know when lean one way or the other? Are there some rules of thumb? When should theory guide us, vs. anecdotal experiences? Gaddis gives no firm, falsifiable answers, probably because there are none. And yet the premise of his book is that there are right ways and wrong ways to make these decisions. I suspect the solution is to die before you screw up - like FDR, and unlike Napoleon.

In short, a fun historical read but it talks in circles.