U.S. plans to sell Kuwait 60 Raytheon Patriot PAC-3 air-defense missiles for $4.2 billion are part of a major effort to boost the military capabilities of Washington's Persian Gulf allies confronting Iran.

In part, the weapons, and others being sold to the gulf monarchies in a massive upgrading of their defense systems, are intended to minimize the number of U.S. forces being deployed in the region to confront an expansionist Iran.

The deal, which needs U.S. congressional approval, comes amid a major defense buying spree by the Emirates, which has one of the strongest air forces in the gulf and is arguably more strike-oriented than the Saudi air force.

The emirates leadership is mulling the purchase of the V-22 Osprey tilt-rotor aircraft built by Boeing Bell of the United States.

Aerospace Daily and Defense Report said negotiations for the sale to the Emirates are now in their final stages.

On Dec. 25, 2011, the Emirates signed a $4.3 billion contract with Lockheed Martin for two batteries of its Terminal High Altitude Area Defense missile system, including two Raytheon AN-TPY-2 X-band long-range radars and 96 interceptors.

The Emirates had originally sought four batteries, with 144 interceptors and four radar systems for $6.9 billion, but cut that back in 2010.

That was the first foreign sale for THAAD, no doubt accelerated because of the deteriorating standoff with Iran and the threat to 35 percent of global oil supplies that originate in the gulf.

The contract certainly underlined U.S. efforts to rapidly build up the defense -- and strike -- capabilities of the gulf monarchies led by Saudi Arabia to counteract Iran's ballistic missile buildup and the threat from its naval forces.

Veteran Middle East defense analyst Anthony Cordesman of the Center for Strategic and International Studies in Washington, said U.S. President Barack Obama's administration seeks to achieve "a new post-Iraq war security structure that can secure the flow of energy exports to the global economy."

The centerpiece of this effort is the massive 20-year, $67 billion arms package for Saudi Arabia, which had its origins during the George W. Bush administration and that includes combat jets, armor, missiles and warships.

All told, the Persian Gulf monarchies are expected to spend $123 billion on arms, mainly American systems, over the next four or five years.

That's one of the largest peacetime rearmament exercises ever undertaken.

The oil- and gas-rich Emirates alone is slated to spend $35 billion-$40 billion, says Theodore Karasik of the Institute for Near East and Gulf Military Analysis in Dubai, the Emirates' financial hub.

The Emirates has also signed up to acquire Raytheon's most advanced MIM-104 Patriot system, the PAC-3, with 20 launchers and four radar systems and control stations. The contract includes training programs.

The Patriot Advanced Capability -- PAC-3 -- is the variant destined for Kuwait, which currently fields older models. It bought 210 earlier generation models, with 25 launchers, in 1992. It bought 140 PAC-2 variants in 2007.

The PAC-3 system contains a fire-control section consisting of the AN/MPQ-53 or -65 radar, the AN/MSQ-104 Engagement Control Station, the OE-349 Antenna Mast Group and the EPP-III electric power plant.

The M901 launcher can carry up to 16 PAC-3 interceptors.

The United States is reportedly building a missile defense radar station at a covert location in the tiny emirate of Qatar, which borders Saudi Arabia in the southern gulf.

This is believed to be an X-band radar, probably Raytheon's mobile AN/TPY-2 system that can detect missile launches 1,500 miles away via satellite surveillance.

This system was installed at Mount Keren in Israel's Negev Desert in 2008 to improve the Jewish state's early network. The AN/TPY-2 gives Israel as much as two minutes' extra warning time than its own systems.

That X-band radar is manned by U.S. forces. It's not clear whether the one reportedly being installed in Qatar will eventually be acquired by the emirate.