Anti-ship ballistic missile

An anti-ship ballistic missile (ASBM) is a military quasiballistic missile system designed to hit a warship at sea.

The ASBM's conventional warhead and kinetic energy may be sufficient to cripple or outright destroy a supercarrier with a single hit. However, unlike a nuclear warhead, this will require a direct hit to be effective. Thus, and unlike a typical ballistic missile, which follows a ballistic flightpath after the relatively brief initial powered phase of flight, an ASBM would require a precise and high-performance terminal guidance system, with in-flight updates or advanced sensors in order to hit its moving target.

China
China has designed the world's first anti-ship ballistic missile, known as the DF-21D. In 2010, it was reported that China had entered the DF-21D into its early operational stage for deployment. The potential threat from the DF-21D against US aircraft carriers has reportedly caused major changes in US strategy.

Iran
In February 2011, Iran demonstrated a short-range anti-ship ballistic missile named Persian Gulf or Khalij Fars, a missile based on the Fateh-110 which successfully hit a stationary target vessel. It has been reported as a short ranged ballistic missile with a range of 250–300 km.

Countermeasures
The United States Navy allegedly fields what some experts think to be the best midcourse anti-ballistic defense in the world, and is developing high powered lasers for terminal-defense against anti-ship ballistic missiles. The U.S. arsenal has a variety of potential countermeasures. According to a senior political scientist at the RAND Corporation, Roger Cliff, "“The thing to keep in mind is that, in order for China to successfully attack a U.S. navy ship with a ballistic missile, it must first detect the ship, identify it as a U.S. warship of a type that it wishes to attack (e.g., an aircraft carrier), acquire a precise enough measurement of its location that a missile can be launched at it (i.e., a one-hour old satellite photograph is probably useless, as the ship could be 25 miles away from where it was when the picture was taken), and then provide mid-course updates to the missile. Finally, the warhead must lock onto and home in on the ship. This complicated “kill chain” provides a number of opportunities to defeat the attack. For example, over-the-horizon radars used to detect ships can be jammed, spoofed, or destroyed; smoke and other obscurants can be deployed when an imagery satellite, which follows a predictable orbit, is passing over a formation of ships; the mid-course updates can be jammed; and when the missile locks on to the target its seeker can be jammed or spoofed. Actually intercepting the missile is probably the most difficult thing to do. [...]The missile by itself would be pretty useless. As implied by my response to the previous question, an entire “system of systems” is needed to make it work. Some countries might buy them just to impress their neighbors, but their combat effectiveness would be negligible unless the country also invested in the needed detection, data processing, and communications systems.”"