By Adam Entous and Jim Wolf
WASHINGTON (Reuters) - The Obama administration is working toward a Middle East missile defense that envisions adding an advanced radar site in a Gulf state to one already in Israel to thwart any Iranian attack, U.S. officials said.
The Obama administration has been quietly helping Arab states boost their missile defenses with the goal of tying them into one system. The process could take two or three more years, officials said.
The emerging Middle East plan resembles the "phased adaptive approach" President Barack Obama rolled out with much fanfare last September to integrate sea- and land-based missile defenses in and around U.S. NATO allies in Europe.
The Middle East buildup has been played down because of Arab sensitivities about U.S. military involvement and skittishness about any military cooperation with Israel, where the United States based a high-powered X-Band radar in 2008 to bolster Israel's missile defenses.
U.S. military strategists believe a second high-powered AN/TPY-2 transportable radar in a Gulf state would boost the capabilities of the proposed regional missile umbrella. A candidate country to host it has not yet stepped forward.
U.S. officials want the new radar in the Gulf to be positioned in a location that would allow it to work with the AN/TPY-2 radar in southern Israel, which is operated by U.S. personnel. Built by Raytheon Co, the system locks on to targets in their boost, midcourse and terminal phases.
"The idea (of a regional security umbrella) has been out there for a while but the specific pieces are now starting to fall into place," a military official said.
A diplomat from the region called the approach "plug and play" -- first the building blocks of the system are put in place, then they are linked together and turned on.
The only other deployed AN/TPY-2 system was set up in 2006 in Shariki, Japan, as a hedge against missiles that could be fired by North Korea.
The missile defense buildup in Gulf states began under former President George W. Bush. It has accelerated under Obama, who is pushing for a new round of U.N. sanctions against Iran over its suspected nuclear weapons program. Iran says its program is to generate electricity.
Officials said linking two X-Band radar sites in the Middle East with Patriot and Terminal High Altitude Area Defense, or THAAD, anti-missile systems was more a political hurdle than a technical one. At issue, among other things, is cooperation among Arab states that have a long history of mistrust.
Secretary of State Hillary Clinton first proposed that Washington bring Middle Eastern nations under what she called a security "umbrella" to neutralize any Iranian missile launches. Some U.S. critics assailed her statement as an implicit admission that a nuclear-armed Iran was inevitable.
Kenneth Katzman, an expert on regional security issues, said Gulf states had boosted their ability to operate jointly with the Pentagon on increasingly advanced systems.
"This has improved the prospects for implementing a long-standing vision of a potential region-wide missile defense system," said Katzman of the Congressional Research Service.
The deployments include expanded land-based Patriot defensive missile installations in Kuwait, Qatar, the United Arab Emirates and Bahrain, but the numbers are expected to grow, officials said.
Officials said the AN/TPY-2 system worked best when the installations were arrayed along an arc around the perceived threat area. It is unclear which Gulf state might agree to host a second regional X-Band radar, although three or four are viewed as potential candidates.
The Pentagon's Defense Security Cooperation Agency notified Congress in September 2008 of a proposed sale of THAAD units worth up to $7 billion to the United Arab Emirates. The AN/TPY-2 may be configured as part of the THAAD system.
The House of Representatives' Armed Services Committee approved last week $65 million as a kind of down-payment on more AN/TPY-2 radars. The provision was added to its version of a 2011 defense bill being debated by the full House.
Since the X-Band radar site at Israel's Nevatim air base in the Negev desert is said to be staffed by U.S. forces, rather than Israelis, U.S. officials say a link-up may be acceptable to Arabs who might otherwise balk at cooperating with the Jewish state against Iran's Islamic authorities.
The two main radar arrays would mesh other sensors and weapons systems like the Patriot PAC-3 anti-missile. That would let each country detect Iranian missiles at the same time and then choose which systems to go after them, officials said.
The shared early warning system could be integrated with U.S. Navy cruisers and destroyers equipped with the Aegis ballistic missile defense system in offshore waters.
Iran's advances in missile technology and defiance of the United Nations have helped persuade Arab states to work more closely together on missile defenses, officials said.
U.S. officials also pointed to signs the perceived Iranian threat has at least in private helped open doors to Israeli-Arab cooperation unimaginable even a few years ago.
Israel is already on track to mesh more closely into the U.S. antimissile bulwark, military officials say.
Obama's approach is seen as good news for Raytheon, the world's biggest missile maker, and Lockheed Martin Corp, the Pentagon's No. 1 supplier. They build much of the hardware on which the new systems rely.
(Editing by Patricia Wilson and Peter Cooney)