The island nations that stretch across the South Pacific — sparsely populated atolls and volcanic archipelagos, known more for tourism than lucrative natural resources — may not seem, at first glance, to be a major geopolitical prize.The island nations that stretch across the South Pacific — sparsely populated atolls and volcanic archipelagos, known more for tourism than lucrative natural resources — may not seem, at first glance, to be a major geopolitical prize.