One cannot wage war under present conditions without the support of public opinion, which is tremendously molded by the press and other forms of propaganda.

The remark underscores a modern reality of mass politics: in industrial, media-saturated societies, military action depends not only on matériel and strategy but also on legitimacy in the eyes of the public. MacArthur’s emphasis on the press and “propaganda” points to the way narratives—about threats, objectives, casualties, and national purpose—shape willingness to fight, fund, and endure war. The quote also implies a constraint on commanders and statesmen: even decisive battlefield advantages can be undermined if public opinion turns, while skillful information management can sustain or expand support. Read critically, it can be taken either as a descriptive warning about democratic accountability or as a candid acknowledgment of the power (and danger) of mass persuasion in wartime.