The Exocet missile is a French-built anti-ship missile that has been in service since 1979. The Exocet missile can deliver a 165 kg explosive warhead to a range of 70-180 km. A sea-skimming missile, the Exocet stays close enough to the water that it can be difficult to pick up on radar. There are several versions of the Exocet missile that can be launched from submarines, surface vessels, or airplanes. Several hundred of these missiles were launched by Iran during the Iran-Iraq war, and a few were launched by Argentina against United Kingdom ships during the Falklands War.
Tuned for doing the greatest possible damage to ships, an Exocet missile can travel at 315 m/s (1134 km/h), meaning it hits most targets within a few minutes from launch at most. This speed is slightly under the speed of sound, which prevents the Exocet missile from creating an easily detectable sonic boom. Beginning its flight solely based on inertia, in mid-flight the missile turns on an internal radar navigational system that helps it hone in on its target.
In 1982, during the Falklands War, between Argentina and the UK over the Falkland Islands off the southeast coast of Argentina, several Exocets were used to devastating effect on the UK Navy. Super Entendard warplanes equipped with Exocet missiles managed to sink the HMS Sheffield, a destroyer, on 4 May, and the 15,000 tonne merchant ship Atlantic Conveyor on 25 May. This made Exocet missiles world-famous. In the UK, the term "Exocet" became shorthand for a devastating attack.
Recently declassified documents make it clear that at the time of the Falklands War, UK military intelligence was very intimidated by the Exocet missiles, worrying about a "nightmare scenario" where one or both of the Navy's aircraft carriers in the area might have been sunk, making recapturing the Falklands much harder. The cost difference between an Exocet and an aircraft carrier is huge -- several million dollars compared to dozens of billions of dollars. The vulnerability of capital ships to anti-ship missile attacks has caused some military strategists to question the value of these ships. Such questions play a role in strategic planning in the United States, especially in context of a possible war with China over Taiwan. Without an effective anti-missile system, nuclear-tipped or conventional Exocets could likely sink much of the US Navy.