The Arabian Gulf is now involved in a massive arms race, triggered largely by the fear that Iran will try to use its military forces to intimidate or dominate its neighbors. Iran has threatened to close the Gulf and carried out a wide range of large military exercises to show its capabilities. And Iran has steadily increased its ability to exploit the threat of conventional and asymmetric warfare to maritime traffic in the Gulf. The buildup of Iran’s naval, air, and missile capabilities poses a wide range of threats to maritime traffic into and outside of the Gulf.