Iran is a major regional power and it is a country.
China , officially the People 's Republic of China ( PRC ) , is a unitary sovereign state in East Asia and the world 's most populous country , with a population of over 1.381 billion . Iran . It is the only country with both a Caspian Sea and an Indian Ocean coastline . Iran is a major regional and middle power , and its large reserves of fossil fuels -- which include the largest natural gas supply in the world and the fourth-largest proven oil reserves -- exert considerable influence in international energy security and the world economy .