The U.S. Defense Department's disclosure of an impending sale of advanced weaponry worth $10 billion to Israel, Saudi Arabia and the United Arab Emirates underlines the alarming scale of arms purchases in a region seething with crisis and conflict.

The U.S. administration of President Barack Obama says the deal, which took a year of secret negotiations to put together, is essential to beef up the defenses of the three countries to counter Iran's expansionist policies.

But given the growing reliance of the U.S. defense sector on export sales to counter the large-scale cutback in defense spending, domestic political pressure probably had a lot to do with formulating the arms package.

And Obama's oft-repeated pledge to Israel to maintain its military superiority in the region, despite the demands of slashing U.S. spending, likely was involved as well, if only to persuade Israeli Prime Minister Binyamin Netanyahu not to unleash unilateral pre-emotive strikes against Iran's nuclear program.

Providing advanced systems to Saudi Arabia and the Emirates, which are also at odds with Iran and infinitely more vulnerable to Tehran's missiles than Israel, can also be justified by the concept of using those monarchies as a buffer between the Jewish state and the Islamic Republic.

That way, the Pentagon can undercut Israeli concerns about supplying key Arab states, particularly two that in reality pose little threat to Israel, with advanced weaponry.

The Pentagon was at pains to stress that the Arab monarchies won't get the most advanced systems which are reserved only for Israel.

Such ploys are necessary for the Pentagon if it wants to placate pro-Israeli lawmakers in Congress and the powerful Israel lobby in Washington opposing such sales to Arab states.

This time there have been no apparent objections from Israel, as there were none when Washington announced a whopping $29.5 billion arms package to Saudi Arabia two years ago.

There was a time when such deals elicited diplomatic broadsides from the Jewish state but the geopolitical landscape in the Middle East has changed dramatically in recent years, with Israel now watching Iran's nuclear program and Tehran's development of intermediate-range ballistic missiles that are becoming a serious conventional threat.

It's significant that the Obama administration is to supply Israel with systems that will be vital for hitting Iran's heavily defended nuclear facilities, such as anti-radiation missiles capable of taking out air-defense radars, improved radars for Israeli jets and an undisclosed number of new-generation KC-135 aerial tankers built by the Boeing Co.

The strength of the long-range air attacks against Iran that Israel can mount is limited to the number of aerial tankers it has to refuel the fighters going in and coming out. At present it's believed to have seven KC-707 tankers -- not enough to sustain a large-scale air assault of 30-40 F-15I and F-16I strike jets.

The configuration of the new arms deals may mollify Israeli opinion but this hasn't stopped several Israeli leaders, including the new defense minister, former Gen. Moshe Yaalon, and Chief of Staff Lt. Gen. Benny Gantz, from warning the Jewish state it must prepare for the possibility of having to hit Iran on its own.

The multi-country U.S. arms deal will mark a huge hike in the collective defense spending of the Middle East and North Africa, which totaled $166 billion in 2012, the International Institute for Strategic Studies in London said.

That works out at $1 in every $10 spent on defense by the world's armed forces in 2012 came from the region. That's the equivalent of around 5.3 percent of the region's gross domestic product, slightly up from 5.2 percent in 2011.

Regionally, Saudi Arabia spent the most with an estimated defense budget of $52.5 billion, the IISS reported. Next was Iran, which allocated $23.09 billion.

Despite its vast expenditure on arms, Saudi Arabia only ranked third in the region in terms of defense spending per capita. At $1,979 per person, it trailed behind Israel, which spent $2,551 per capita in 2012, and the Persian Gulf sultanate of Oman at $2,178.

Last year, defense analysts estimated that Saudi Arabia and its partners in the Gulf Cooperation Council planned to spend $122 billion between them on advanced weaponry in their confrontation with Iran.