In what ways did the US respond to Japan's expansion before Pearl Harbor?

The US responded to Japan's expansion before Pearl Harbor primarily through economic sanctions and diplomatic negotiations.

In the 1930s, Japan's aggressive expansion into China and Southeast Asia raised international concerns. The US, as a major global power, felt compelled to respond. The primary method of response was economic sanctions. In 1938, the US began to impose restrictions on the export of aircraft and parts to Japan, which was a significant blow to Japan's military capabilities. This was followed by further restrictions on the export of iron, steel, and oil, which were crucial for Japan's war effort. The US also froze Japanese assets in the country, effectively cutting off Japan from a significant source of funding.

Simultaneously, the US engaged in diplomatic negotiations with Japan. The Hull-Nomura talks, named after US Secretary of State Cordell Hull and Japanese Ambassador Kichisaburo Nomura, were a series of negotiations aimed at resolving the tensions between the two countries. The US demanded that Japan withdraw from China and Indochina, and in return, the US would lift the economic sanctions. However, these talks ultimately failed as Japan was unwilling to relinquish its territorial gains.

The US also sought to contain Japan's expansion through military preparedness. The US increased its military presence in the Pacific, particularly in the Philippines, which was a US territory at the time. The US also provided aid to China, which was at war with Japan. This included the provision of military advisors and equipment, as well as financial aid.

In addition, the US tried to rally international opposition against Japan's expansion. The US advocated for collective security and sought to strengthen the international order through institutions like the League of Nations. However, these efforts were largely unsuccessful due to the isolationist policies of many countries during this period.

In summary, the US response to Japan's expansion before Pearl Harbor was multifaceted, involving economic sanctions, diplomatic negotiations, military preparedness, and attempts to rally international opposition. Despite these efforts, the US was unable to prevent Japan's attack on Pearl Harbor, which led to the US's entry into World War II.