Final answer:
Attempts at preserving peace in the 1920s and 1930s included the Treaty of Versailles and the formation of the League of Nations, alongside international treaties like the Washington Naval Conference and the Kellogg-Briand Pact; however, these initiatives lacked effective enforcement and ultimately failed to prevent World War II.
Step-by-step explanation:
During the 1920s and 1930s, there were several attempts at preserving peace following the devastation of World War I. The Treaty of Versailles redrew the map of Europe and imposed harsh penalties on Germany, which were intended to prevent further aggression but instead sowed seeds of discontent. The establishment of the League of Nations was a significant attempt at collective security, aimed at diplomatic resolution of conflicts to avoid war. Despite these efforts, both the Treaty of Versailles and the League of Nations had inherent weaknesses. For instance, the League of Nations lacked enforcement power and the United States did not join, undercutting its effectiveness. Additionally, international diplomacy resulted in several treaties aimed at reducing the chance of conflict, such as the Washington Naval Conference and the Kellogg-Briand Pact, which were efforts to reduce armaments and declared war an international crime, respectively. However, these treaties lacked mechanisms to enforce compliance, ultimately proving to be ineffective as aggressive actions by nations went unchecked, leading to the outbreak of World War II.