Using Carl von Clausewitz’s “trinity” as a framework for analysis, this article compares the performances of Generals Arthur Percival and Douglas MacArthur as commanders during the Malayan and Philippine campaigns in World War II respectively. Both campaigns ultimately ended in defeat by the Japanese, and this study evaluates the generals’ leadership, decision-making, and adaptation. The conclusion is that MacArthur’s performance surpassed that of Percival’s, and this highlights the importance of situational awareness, assertiveness, as well as adaptability in effective generalship.