INTERNATIONAL environmentalist Jacques Cousteau has called for a permanent ban on mining in Antarctica, which he said would destroy "this last unspoiled continent of the planet." . . . A LIBERIAN GENERAL who has occupied the executive mansion since President Samuel Doe was killed rejected demands from an international peacekeeping force Monday that his remaining troops surrender. . . . PAKISTAN'S government has ordered four Indian diplomats expelled for "undesirable activities" in the latest blow to deteriorating relations between the two countries.