Question

Which development of the 1930s led most directly to the United States

Answer 1

Japan's seizure of European colonies in Asia led United States  directly entering into World War II.

Explanation:

There was a cordial relationship between America and Japan when remained trading partners (America supplied Oil to Japan). Then tension started when Japan first expanded its territory over Manchuria in 1931.

It then tried to occupy China and that resulted in the Sino-Japanese war. France, British, and the U.S. were supplying goods to China during the war.

Japan's main goal was to capture Singapore. Also, it had plans on occupying Malay which was under British control. America asked to Japan to withdraw its conquest idea.

So it attacked Pearl Harbor (where military naval base was situated) to prevent the US from interfering its invasion. This attack on Pearl Harbor made the U.S. enter into WW II.