George Catlett Marshall is one of those figures whose importance becomes clearer the longer one studies him and more puzzling the more one tries to summarize him neatly. He does not lend himself to slogans or cinematic shorthand. There is no single moment that captures him, no battlefield pose that defines his legacy. Instead there is a long accumulation of decisions, habits, and silences that, taken together, helped shape the American century. He was the only American to serve as Army Chief of Staff, Secretary of State, and Secretary of Defense, and he did so without ever behaving as though history owed him attention. That alone should give modern audiences pause.