The term "Miracle on the Han River" was coined after the phrase "Miracle on the Rhine" was used to refer to the economic rebirth of West Germany after World War II. This analogy was incorporated by Chang Myon, prime minister of the Second Republic of South Korea, in his New Year's address of 1961, in which he encouraged South Koreans to bear difficulties in the hope of achieving a similar economic upturn. The resultant growth has been attributed to the hard work of the labor force. External factors include the enormous economic and technical assistance provided by the Western countries, particularly Japan (see Treaty on Basic Relations between Japan and the Republic of Korea) and the United States, access to Western and Japanese markets, and the acquisition of foreign currency by Korean migrant workers in the early stages of economic growth.