This is an interesting book that discusses Warfare as it evolved from 1945-the Present.
Overall, I found this book to be an odd combination. While a majority of the chapters offer true insight into the ways in which war changed, from the beginning of Air Combat as a major feature of war, to the ways in which Counter-insurgency played a major part in many of the wars that have consumed the West. Yet, at the same time, the book at times seems incongruous. Small sections on the South Ossetian War, Rwanda, and arguably part of the Balkan Wars that offered little to the overall point of the book. I also found that a lot of the book was more or less a lead up to the Wars in Afghanistan and Iraq, which Petraeus offers great commentary on, as well as analysis. His section on Iraq and Afghanistan also offers points of failure throughout the tenure there, but at the same time, it does come across, at times, as a deflection from the fact that, arguably, the Global War on Terror, particularly in Afghanistan, is another Vietnam for America, wherein it failed to reach its goals.
I also found the chapter on Ukraine to be enlightening, offering insights into the War and into Putin's successes and failures. The section on Gaza, however, falls flat, with no real analysis of the war (which, given the fact the book was published during the war, makes sense), although he does showcase the ways in which the modern world with its technology has made even regional wars a product of a wider, worldwide community, where everyone has opinions, and the Court of Public Opinion's role in optics of war, and how there are often (un)intended consequences to actions.