Recently revealed (via Wikileaks) American diplomatic messages confirmed what has long been reported here, that the Arab Gulf states are alarmed at the growing military power and aggression of Iran. These fears are being addressed in a very concrete way, with massive purchases of American anti-aircraft and anti-missile systems. Two years ago the UAE (United Arab Emirates) ordered $7 billion worth of American THAAD (Terminal High Altitude Area Defense) anti-missile systems to protect itself against the growing arsenal of Iranian ballistic missiles. The UAE is a confederation of small Arab states at the southern end of the Persian Gulf. With a population of only 5.5 million, and large oil and gas deposits. The emirates have a per-capita income of $43,000. Thus the UAE has a lot to defend, and an increasingly belligerent neighbor just across the Gulf. The UAE controls one side of the entrance to the Gulf (the Straits of Hormuz). Iran is on the other side, and both nations dispute ownership of some islands in the middle. The THAAD order consisted of three THAAD batteries with 147 anti-ballistic missiles, four Radar Sets (including one spare), six Fire and Control Communication stations, and nine launchers.
THAAD has been in development for over two decades. Ultimately, the U.S. Army would like to buy at least 18 launchers, 1,400 missiles, and 18 radars. The UAE appears to plan eventually buying more than that; at least a dozen batteries, which is enough to cover the entire southern end of the Persian Gulf against whatever the Iranians can throw at them. However, it will be at least three years before any of the UAE THAADs are deployed. With an order that size, perhaps the U.S. will throw in some temporary protection via U.S. Navy warships equipped with Aegis anti-missile missiles.
THAAD is a step up from the Patriot PAC-3 anti-missile (which is an anti-aircraft missile adapted to take out incoming missiles). The PAC-3 works, but it has limited (20 kilometers) range. The navy has also modified its Standard anti-aircraft missile system to operate like the PAC-3. This system, the RIM-161A, also known as the Standard Missile 3 (or SM-3), has a longer range than THAAD (over 500 kilometers) and max altitude of 160 kilometers. The Standard 3 is based on the failed anti-missile version of the Standard 2, and costs over three million dollars each. The Standard 3 has four stages. The first two stages boost the interceptor out of the atmosphere. The third stage fires twice to boost the interceptor farther beyond the earth's atmosphere. Prior to each motor firing it takes a GPS reading to correct course for approaching the target. The fourth stage is the nine kg (20 pound) LEAP kill vehicle, which uses infrared sensors to close on the target and ram it.
The UAE has already bought Patriot anti-missile and anti-aircraft missile systems, as well as dozens of new fighter interceptors, and tens of billions of dollars of new gear for their army and navy. The UAE armed forces has 60,000 troops, and they are armed to the teeth. Saudi Arabia and Kuwait have also been stocking up on anti-aircraft missiles, helicopters, GPS guided rockets, warplanes and armored vehicles. But the Arabs also know that the Iranian troops tend to be more effective than their Arab counterparts, and there are 73 million Iranians, compared to less than half as many Arabs on the other side of the Gulf.