In October Iran announced that it had developed and tested a more precise guidance system for its Shahab 3 IRBM (Intermediate Range Ballistic Missile). This upgrade is believed capable of landing the warhead within a few hundred meters of its aiming point. Since the warhead of the Shahab 3 is no more than a ton, this improved accuracy would only be useful if the Shahab 3 had a nuclear warhead. Iran says it does not yet have a nuclear warhead for this missile yet. The original Shahab 3 would land somewhere within a circle nearly a thousand meters in diameter, making it useful only for bombarding large targets (cities).
Shahab 3 was developed rto threaten Israel and Iran’s Arab neighbors. Back in 2009 Iran was spotted (from the air) building a fortified missile storage and launch complex for at least fifteen Shahab 3 missiles outside Khorramabad (near the Iraq border in the Zagros mountains). This was the Imam Ali missile base operated by the Revolutionary Guard Corps. Iran is aware that both the Israelis and Arabs are creating the ability to quickly find and destroy Iranian ballistic missiles if there is a war.
The Shahab 3 missile is basically 1960s technology, with the addition of GPS guidance. Russian and North Korean missile technology was obtained to make the Shahab 3 work. This resulted in a missile that apparently will function properly about 80 percent of the time, and deliver a warhead of about one ton, to a range of some 1,300 kilometers. By world standards this is a pretty effective weapon. Range has since been increased to 1,700 kilometers and the liquid fuel propulsion has been replaced by solid fuel.
The Shahab 3 normally travels on a tractor trailer rig that can also raise the missile into a launch position. But it takes several hours to fuel the liquid fuel version and otherwise prepare it for launch. The solid fuel version can be ready to fire in less than thirty minutes. The Iranian tactics are to drive the missiles and out to a remote location for erecting and launching. The Khorramabad base also shows signs of silo construction.
Iran is believed to have been building Shahab 3s since 2004, even though they continue to refine the design, and conduct test firings. Iran is believed to have about a hundred Shahab 3s, and is building about one a month. There are indications that production has increased. Israel was always seen as the main target. Iran has threatened Israel with destruction, often rather openly. Shahab 3's could be fired with high explosive warheads, and hit, with enough accuracy, to kill mostly Jews, and not Israeli Arabs or Palestinians. Iran also has chemical (nerve gas) warheads, and Israel has threatened nuclear retaliation if they get hit by chemical warheads.