BERLIN -- Junichiro Koizumi will resign as the Japanese prime minister at the end of this month and be replaced by Chief Cabinet Secretary Shinzo Abe. Koizumi became prime minister in April 2001. After more than five years as prime minister, Koizumi's political record is checkered: He achieved big successes with domestic reforms and economic recovery, but caused a political disaster in relations with Japan's most important neighbors, China and South Korea.