ABU DHABI Distrust among Sunni Gulf Arab states has scuppered the installation of a joint missile shield which Washington has long urged as the best means of defense against any strike by Iran.
The oil-exporting states have spent billions on U.S.-built anti-missile platforms but have fallen short of building a unified umbrella and an early warning system, despite their expressed intention to do so.
Analysts say that although they belong to the same political and military alliance, the six Gulf Cooperation Council (GCC)members remain uneasy about sharing data. Nor can they decide on the location of a central command and are struggling to find ways to work together in case of an emergency.
"The question is not only about trust among Gulf states but also trust in the Americans," said Mustafa Alani, a Middle East defense analyst. "The central command is going to be controlled by a powerful state (Saudi Arabia) and the Americans and the small states will be sandwiched between the two."
U.S. officials say the missile shield is part of a global plan that includes deployment of sea and land-based systems in Europe, the Middle East and Asia to counter the threat of ballistic missiles from states like Iran and North Korea.
Iran is at odds with its Gulf Arab neighbors and the West over its nuclear program. The United States and its allies say Iran is seeking nuclear weapons capability under the cover of a civil program, which Tehran denies.
The Islamic state has threatened to target U.S. interests in the Gulf, including military bases, and to block oil tanker lanes in the Strait of Hormuz if it is attacked.
U.S. officials have been talking for years to the GCC members - Bahrain, Kuwait, Oman, Qatar, Saudi Arabia and the United Arab Emirates - about building the shield but have done so with more urgency in recent months.
The site of the central command room is a thorny issue because the Gulf states have a long history of disaccord. In 2009, the UAE pulled out of a planned GCC monetary union after Saudi Arabia was voted as the host of a common central bank. Saudi Arabia also hosts the GCC headquarters.
"We have to have a location," Lt Gen David Goldfein, the U.S. Air Force commander for southwest Asia, told a security conference in Abu Dhabi
The UAE and Saudi Arabia are likely to vie for hosting the headquarters. Heavyweight Saudi Arabia is also home to the Peninsula Shield, a GCC force set up in 1986 to defend Gulf countries against any potential threat.
It has been called upon three times since its foundation - in the 1990-91 Gulf War, during the U.S.-led invasion of Iraq in 2003 and in March 2011 when Saudi Arabia and the UAE sent 1,500 soldiers to Bahrain during anti-government Shi'ite protests.
Theodore Karasik, a Dubai-based security analyst, said the UAE would be the favored host because "this is where the push for integration has started from."
Experts suggest the best short-term solution is for Gulf states to acquire compatible systems that can be, as one official said, "plugged" together in case of emergencies.
But U.S. officials say a "plug and play" approach is too risky, suggesting that it is no alternative to a central command which allows for a much faster decision-making process.
In this case, commanders would be sitting in one room controlling the entire network rather than having to coordinate between six different commands.
Goldfein said that despite each country's individual defense plans and bilateral defense arrangements with the United States, a multilateral security approach was still needed.
WARY OF INFORMATION SHARING
Analysts say the Gulf states are not only wary of sharing information among themselves but also with the United States because the oil exporters fear direct U.S. involvement in the shield could mean that it would link its systems to GCC radars without sharing back data collected by its own assets.
GCC Secretary-General Abdullatif al-Zayani was among those at the Abu Dhabi conference who questioned the bloc's dependence on foreign allies, mainly the United States.
"What are the defense capabilities that the GCC needs to become less dependent on their allies?" he asked.
Alani said another obstacle to regional cooperation was related to finances and sovereignty.
"Many countries either don't have the money or don't want to relinquish national control," he said.
Smaller countries are concerned that states who would contribute more to the system such as Saudi Arabia and the UAE would have more control over it.
Despite a closing of ranks during the 1990-91 crisis over Iraq's invasion of Kuwait, Gulf states belonging to the Saudi-dominated GCC have tended to guard their sovereignty jealously. Long-running border disputes have slowed security coordination.
"The GCC is overall a fractious organization. They weren't able to agree on a common currency and it's rare they have real consensus among themselves," Robert Jordan, the U.S. ambassador to Riyadh from 2001-03, told Reuters.
"The Saudis are viewed by the others as the 800lb gorilla in the region and are perceived to throw their weight about."
Any pan-Gulf defense shield would have to be supervised by the Americans, which makes some countries, especially Saudi Arabia, have seconds thoughts about taking part, a Gulf-based diplomat said.
"The Americans want the system for their own reasons and defense assessment, but yet they want the Gulf to pay for it and host it," he said.
The missile defense buildup in the Gulf began under former U.S. President George W. Bush and accelerated under President Barack Obama, whose administration introduced tougher sanctions against Iran.
A 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.
The Gulf states have individually acquired some advanced defense systems, including the latest versions of the Patriot Air and Missile Defense System. UAE has spent billions in recent years to protect its cities and oil installations against missile attacks.
The latest deal was signed in December with Lockheed Martin Corp for a $3.6 billion Theater High Altitude Area Defense (THAAD) - the only system designed to destroy short- and intermediate-range ballistic missiles both inside and outside the Earth's atmosphere.
A company official told Reuters he expected other Gulf states to buy the THAAD as a result of tensions with Iran.
Besides Lockheed Martin, the biggest U.S. missile defense contractors include Boeing Co, Raytheon Co and Northrop Grumman Corp. Even without a central command system, much of the Gulf would be covered within a few years with the deployment of new systems in the region.
(Writing by Mahmoud Habboush; Additional reporting by Raissa Kasolowsky; Editing by Angus MacSwan)