Final answer:
In the 1920s, the U.S. used economic policies and arms agreements, such as dollar diplomacy and international treaties, to influence global policy without resorting to military force, reflecting a broad national sentiment of isolationism.
Step-by-step explanation:
Rather than relying on armed force to influence global policy during the 1920s, the U.S. used economic policies and arms agreements. After World War I, President Woodrow Wilson's vision for collective security in international relations was embodied in the League of Nations. However, the League found it difficult to enforce its resolutions, as seen in incidents involving Japanese expansion into Manchuria and Italian aggression in Ethiopia. Economic sanctions by the League were largely ineffective due to lack of military enforcement capability.
Domestically, U.S. presidents like William Howard Taft employed strategies such as "dollar diplomacy" to exert influence abroad, endorsing the use of American economic strength to secure financial and political interests without resorting to outright military intervention. This approach mirrored an American public generally averse to additional entanglements in European conflicts, thus fostering a spirit of isolationism during the interwar period. Taft's policy aimed to "substitute dollars for bullets" as a method of maintaining and expanding U.S. influence.
As a result, throughout the 1920s, under Presidents Harding, Coolidge, and Hoover, U.S. foreign policy gravitated towards using its economic prowess and diplomatic influence—embodied in treaties like the Kellogg-Briand Pact—to shape global relations. Despite the national sentiment of keeping a safe distance from international conflicts, economic engagement and agreements on arms reduction were the principal American tools for influencing global policy without resorting to military force.