How did Japan ensure a surprise attack

In early 1941, Admiral Isoroku Yamamoto first proposed a surprise attack on Pearl Harbor, an idea that was contrary to long-standing Japanese strategic doctrine. After the plan's acceptance nearly nine months later, U.S. intelligence failed to detect the 180-degree change in Japanese naval thinking.

Explanation:

he was in office from 1929 to 1933 and served as a reform governor, promoting programs to combat the economic crisis besetting the united states at the time. in the 1932 presidential election, roosevelt defeated republican president herbert hoover in a landslide.

explanation:

it affected it because the kingdoms (with trade) slowly got richer and richer.