There are three ways to look at the Obama administration's historic arms deal with Saudia Arabia announced earlier today: Through the lens of geopolitics, domestic politics, or both. But one thing's for sure: A decade ago, the idea of giving the country that birthed the 9/11 hijackers 84 new Boeing F-15 fighter jets would get laughed out of Congress. "A deal like this would have simply inflamed the foam-at-the-mouth crowd," the Council on Foreign Relations' Thomas Lippman tells Christian Science Monitor. "They must have calculated that it won’t." The package also includes upgrades to 70 other jets, Joint Direct Attack Munitions and the sale of 72 Black Hawk helicopters, 70 Apaches and 36 Little Birds, reports The Wall Street JournalCongress signed off on the $60 billion deal, the largest overseas arms deal in history, last year but only now has the Obama administration forged a deal. Why now? Here are the different theories:

It's about intimidating Iran "Its timing is laden with significance, with tensions over Iran mounting and the United States pulling its last soldiers out of Iraq," reports The New York Times. "The administration announced the sale during a week when Iranian officials threatened to close the strategically vital Straits of Hormuz in response to indications that the United States planned to impose tough sanctions on Iranian oil exports." Going into more detail, The Washington Post notes that Saudi Arabia, "which has a predominantly Sunni Muslim population, and Iran, mostly Shiite, have competed for regional influence for decades, and the Obama administration has sought to bolster its security relationship with Riyadh, despite their differences over the response to the Arab Spring."

It's about curbing unemployment ahead of the elections Andrew Exum at the Center for New American Security sees political calculations in the decision. "This is also ... about U.S. jobs," he writes. "Boeing* had been manufacturing F-15s on its St. Louis assembly line for the past few years without a firm assurance those aircraft would ever be sold. Cancelling the deal with Saudi Arabia would have been a tremendous blow to both Boeing and the people of St. Louis. I am not among those who argue we should keep U.S. defense spending high in order to support the U.S. economy, but in this case, I think it is naive to assume U.S. domestic politics did not play at least a small role in this sale. I'm sure the congressional delegation of Missouri, for example, is enjoying a late Christmas present today." He adds that President Obama barely lost Missouri in his 2008 presidential bid. And just to put some numbers on the decision, deputy press secretary Joshua Earnest said the deal "would support more than 50,000 American jobs, engage 600 suppliers in 44 states, and provide $3.5 billion in annual economic impact to the U.S. economy," reports National Journal. 
 
It's because Israel is finally OK with the decision The Christian Science Monitor argues that Israel's volte-face on the deal played a major part in the trade going through:
 

Such a deal would also have been adamantly opposed by Israel years ago. During the 1980s, Israel opposed the sale of aircraft and missiles to Jordan and Saudi Arabia, according to a 2004 Congressional Research Service briefing. In 1986, the Senate blockedPresident Reagan’s sale of shoulder-launched “Stinger” missiles to Riyadh amid American and Israeli objections – although a denuded arms package eventually went through.

However, the U.S. ally's worries were assuaged, according to CSM, "by assurances that the jets will lack long-range weapons systems and be of a lower grade than those sold to Israel": 

 Defense Minister Ehud Barak has reportedly discussed the deal with US officials and a US Defense Department official told Reuters that Israel is "fairly comfortable" with it overall. As an editorial in The Jerusalem Post recently highlighted, "If the US does not sell to the Gulf states, EU countries or even Russia, which are much less receptive to Israeli interests, might fill the vacuum."