After Japan was defeated in WWII the U.S. led the allies to occupy and rehabilitate the Japanese state. Between 1945-1952 General Douglas A. MacArthur, enacted widespread military, political, economic, and social reforms in Japan. After this the Japanese economy boomed eventually making it the third richest economy in the world.
Fun Fact: "Japan is the third richest economy in the world by nominal GDP and fourth largest by Purchasing Power Parity (PPP) and is the worlds largest developed economy".
