Amid mounting Arab concerns about a rapprochement between the United States and Iran, the Persian Gulf petro-monarchies that are Tehran's greatest opponents are looking to acquire precision-guided weapons and other advanced systems to enhance their strike capabilities.

That has been their main focus at the biannual Dubai Air Show, one of the aerospace industry's major showcases in the region. It opened Sunday and closes Friday.

For decades, the United States has been wary of selling Saudi Arabia and its partners in the Gulf Cooperation Council -- the United Arab Emirates, Kuwait, Qatar, Oman and Bahrain -- such hardware.

This is largely because Washington has pledged to ensure that Israel maintains its qualitative military edge over its regional adversaries -- even if some of the lines are blurring, with both Israel and Saudi Arabia finding common cause in blocking any compromise deal between Washington and Tehran on Iran's nuclear program.

The Europeans have been less constrained in what they sell Arab states, and given the difficulties in marrying the European weapons to the U.S.-built combat jets that make up the air forces of Saudi Arabia and most of its GCC allies, that could influence the new fighters these states are planning to acquire.

That, plus the pressures on U.S. defense companies to ramp up exports to compensate for shrinking defense budgets, could be motivating a change in attitude in Washington on the unofficial ban on precision-guided munitions.

U.S. State Department officials say there's no hard-and-fast policy rule on whether to sell Arab states powerful new advanced systems.

But it's been noticeable that recent arms deals with Arab states in the Persian Gulf in particular have included advanced missile and targeting systems.

This is largely because Washington wants to build up GCC defense capabilities against an expansionist Iran, and the best way to do that is give those states advanced systems that will enhance their capabilities to knock out Iranian missile sites, air-defenses, air bases and naval warships.

All this ensures U.S. defense companies' production lines keep rolling.

Middle Eastern air forces, in particular, "do play a big role in keeping things going," Richard Aboulafia, vice president of analysis at the Teal Group of Virginia, said at the Dubai Air Show.

"They tend to have very diverse fleets with multiple capabilities and multiple arms sources and they tend to pay for the latest and the best."

The Americans have in the last two to three years begun greenlighting the sale of missile defense systems like Lockheed Martin's recent sale of its Terminal High Altitude Area Defense system, or THAAD, to the United Arab Emirates as part of a $3.9 billion deal.

That's not a system that boosts the Emirates' offensive capabilities, but it's indicative of how the Americans are loosening their self-imposed technological restrictions because it's in their interests to do so to ensure Iran is contained to some degree by regional forces.

Israel, too, appears to be less demanding about what U.S. weapons systems go to the gulf states because it sees Iran and its nuclear project, plus its ballistic missile program, more and more as an existential threat.

In October, the Pentagon announced sales to the Emirates and Saudi Arabia of precision systems that had long been unofficially restricted.

The $6.8 billion arms package for the Saudis, without doubt the biggest buyer of U.S. weapons outside the U.S. armed forces, included 650 Boeing AHM-84H standoff land attack missiles-expanded response, or SLAM-ER systems, that until then had pretty much been a no-no.

The Emirates deal, worth around $4 billion, included 300 SLAM-ERs, which are essentially cruise missiles.

Others systems long sought by the key gulf states may now be within reach, U.S. Defense News reported.

It said the Saudis are now hopeful a 2-year-old request for the Paveway IV laser-guided bomb manufactured by Raytheon may soon be met.

Defense News said there are still hurdles to be overcome before the approval process reaches the U.S. Congress, which must approve such sales, but there's growing optimism all round.

If cleared, the weapons would be deployed with Tornado strike jets built by Britain's BAE Systems and the Typhoon built by the Eurofighter consortium of BAE, European defense giant EADS and Finmeccanica of Italy.