The Dolphin-class submarines are not only the most advanced and sophisticated submarines that the Israeli Navy has ever used, they also play a crucial role in the "game" of deterrence in the volatile Middle East region. At extreme moments of tactical or strategic uncertainty, such as in the immediate aftermath of the 9/11 terrorist attacks, Israel’s first walls of defense are its long-range strategic arms – and the most secretive one is the submarine fleet led by the Dolphins.
The Dolphin submarines second-strike capability - in essence, its ability to fire off ballistic missiles against long-range targets in the event of an attack on the Israeli homefront - ensures that Israel's enemies realize that attacking the Jewish state with weapons of mass destruction will definitely be responded to in kind.
The Dolphin submarines can hold approximately 40 sailors onboard at any given time and have been known to take part in training operations around the world. Due to the secrative nature of the submarine fleet, though, Israel does not permit the Dolphins from docking in foreign ports - even in allied countries.
In April 2013, Israel unveiled it fifth Dolphin submarine, the INS Rahav, at a ceremony in Germany. The submarine was purchased after an extensive development and acquisition process led by the Ministry of Defense's Procurement and Production Directorate in cooperation with the Israeli Navy. The Rahav is scheduled to arrive in Israel by the end of 2013, upon completion of the installation of all of its operational systems, and is already considered to be one of the most advanced submarines in the world. It is the most expensive piece of machinery that the Ministry of Defense has procured for the IDF.