TOKYO (AP) - North Korea has launched a campaign to promote the 21-year-old son of leader Kim Jong Il as his successor, Kyodo News reported Saturday. Kim Jong Il turns 61 on Sunday and there is no suggestion that he will step down soon or is in poor health. The Japanese news agency said a classified North Korean military document reverentially referred to Kim's current wife Ko Yong Hee as "mother" and "loyal subject." The North started a similar campaign in the mid-1970s to idolize Kim Jong Il's mother when he was earmarked to succeed his father, Kim Il...