Truman's bad eyesight kept him out, but he snuck in and memorized the eyechart so he could pass the physical and get into the fighting in WWI.
Unlike someone who had "bone spurs" that kept him out of Vietnam and then later disappeared magically.
Trump meanwhile raves about how we don't have "great generals" anymore, specifically name-checking MacArthur as his idol.
Yes, he did! But in each of those decisions, he *followed* advice of *others*. That's what presidents do! They make tough decisions in the face of competing advice.
It's important to remember that Truman devoted his presidency to building up a postwar international order designed to contain Russian influence.