In researching this, I found something so good I feel like almost all of my own comments are be redundant. Please, read this Rand report about the history of American nation-building. It's only 17 pages, does a data analysis it didn't even occur to me was possible, and is well written to boot. That the Rand corporation helped shape a meaningful portion of these efforts shouldn't go unappreciated, and if you're curious why our efforts in Afghanistan seem to have achieved almost nothing, you might find an explanation.
They even immediately notice the same thing that led me to wanting to write this: that American military influence seems ill-matched to achieving the military objectives it was tasked with. If you want to protect the world from communism, and you already have successful domestic PR, wouldn't the best policy to be stopping people from wanting communism so badly? Don't get me wrong, there was a real Red Menace at play, but the Soviets would have been relatively easy to slow down if their only strategy was forcefully conquering every square inch it wanted control of. The Warsaw Pact doesn't establish a counterbalance to the forces of NATO if Poland thinks NATO is pretty swell and the Soviets are monsters, which, it's worth pointing out, is a true statement (gulags had been around for decades and the American internment of Japanese citizens – the closest possible parallel – was substantially more limited in both scope, horror and duration). America and Britain were the good guys, NATO was essentially our international political organization, and siding with us should have been easy.
The modern military, to achieve these more complex desires, sends soldiers, yes, but also doctors, construction workers, utility experts, lawyers, and many more into conflicts. Because we aren't the armies of ancient Greece or even Rome. We do not seek utter annihilation or subjugation of our opponents (even in stopping the Nazis it was more about freeing e.g. France than it was conquering Germany). We want to stop chaos from erupting, establish a friendly government, stop communism, etc. These are all essentially cooperative tasks where terrifying firepower is needed only because they disagree with you. So why not work on the disagreement (considering America is, by and large, the good guy) instead of the firepower?
This is why I'm disappointed when I hear a four-star general say PR, the Internet, and 'hearts and minds' are critical to modern war – but also insist the quintessential soldier is someone who can do a bunch of pushups. It seems like they're so trapped in a conservative institution that they cannot even take themselves seriously. It won't surprise you to learn they understand warfare. It will surprise you that they don't center the military on the elements they describe as crucial and central to every conflict: the will to fight at all. Instead we destroy, realize we hurt people who aren't our enemies, and then rebuild. We're definitely the good guys, but we hardly use that to our advantage at all, despite the 20th centuries' conflicts being largely ideological.
Tomorrow, the penultimate entry in the series discusses talent in the modern military, and the hiring practices America needed to win the world in and outside of combat.