The history of failure in war can almost be summed up in two words: too late.

MacArthur’s aphorism distills a commander’s preoccupation with timing into a blunt diagnosis: many military disasters are not caused by ignorance of what to do, but by delay in doing it. “Too late” can mean late mobilization, late reinforcement, late adaptation to new tactics or technology, or late political decision-making—each allowing an opponent to seize initiative and impose irreversible facts on the ground. The line also reflects MacArthur’s broader strategic temperament, which favored decisive action and bold maneuver over cautious incrementalism. As a general maxim, it warns that in war the window for effective choices narrows quickly, and procrastination can convert manageable risk into catastrophe.