Key Point: Given the volume of valuable commercial shipping in the Persian Gulf, Tehran is investing in improving its ASBMs—and publicizing that effort to the world—as a means to build conventional military deterrence in a context of rising tensions with Saudi Arabia, Israel and the United States.
In 2009, it became clear that China had developed a mobile medium-range ballistic missile called the DF-21D designed to sink ships over 900 miles away. This then-nascent technical achievement gave rise to a still-ongoing debate over the survivability of the U.S.’s nuclear-powered aircraft carriers, as the DF-21D outranged the strike planes serving on carrier decks. This further compelled the U.S. Navy to introduce anti-ballistic missile capability to its destroyers and cruisers in the form of the SM-3 missile.
Ballistic missiles travel in an arcing trajectory to maximize range and velocity, sometimes even exiting the Earth’s atmosphere before plunging down towards their targets at unthinkably fast speeds—in the DF-21’s case, up to ten times the speed of sound. However, until a decade ago there were no operational anti-ship ballistic missiles (though one was developed by the Soviet Union, but did not enter service) because it’s a lot easier to program a ballistic missile to hit a city or military base, than to have one strike a small, moving target—ie, a ship.