SEOUL, Feb. 19 (Yonhap) -- The eldest son of North Korean leader Kim Jong-il is responsible for spreading fake U.S. dollars through Macau, prompting Washington to slap sanctions on the communist country, a South Korean official said Sunday. The U.S. crackdown has not only intensified friction between the two former battlefield foes but also diminished chances for Kim's oldest son, Jong-nam, to succeed his father in a power struggle with his two younger brothers, the intelligence official said, speaking on condition of anonymity. "We obtained intelligence that he got farther away from his father's mind due to the Macau...