Prime Minister Shinzo Abe may be finding it not so easy to live up to his pledge to make Japan a "proactive contributor to peace," as the country ends its troops' participation in a U.N. peacekeeping operation in South Sudan and looks for other missions to join.The U.N. mission in South Sudan was the first test case for the Self-Defense Forces to play a bigger role in international peace-building efforts based on Japan's controversial security legislation, which loosened the constraints of the post-World War II pacifist Constitution.But the SDF members are leaving South Sudan without having…READ FULL ARTICLE