Final answer:
Herbert Hoover worked on improving relations with Latin America through the Clark Memorandum and withdrawing troops, established the Hoover-Stimson Doctrine in response to Japanese aggression, but faced setbacks with the Smoot-Hawley Tariff and the failed Hoover Moratorium.
Step-by-step explanation:
During his presidency, Herbert Hoover took several actions concerning international conflicts and foreign policy. Notably, he played a role in establishing positive relations with Latin American countries by shaping the Clark Memorandum and withdrawing American troops from Haiti and Nicaragua. This set the stage for Franklin Roosevelt's "Good Neighbor" policy. Additionally, Hoover and Secretary of State Henry Stimson outlined the Hoover-Stimson Doctrine, declaring the U.S. would not recognize territories seized by force, as a response to Japan's invasion of Manchuria.
However, Hoover's foreign policy also had its setbacks, such as the implementation of the Smoot-Hawley Tariff, which raised tariffs on imports in an effort to promote American goods but led to trade retaliation by other countries, worsening the global depression. Hoover also proposed the cancelled Hoover Moratorium in a failed attempt to spur the world economy.