The G5+1 talks in Geneva produced an interim agreement limiting Iran’s nuclear program in return for the partial easing of international sanctions. One already obvious outcome is a crisis of confidence in Riyadh regarding the actions and intentions of its longstanding ally and patron, the United States.US-Saudi relations have known ups and downs over the years. Notable downs – the Saudi-led oil embargo in 1973 and the American frustration with Saudi Arabia’s failure to support Egyptian president Anwar Sadat’s peace initiative and the signing of the Camp David Accords with Israel in 1978 – were connected to fundamental differences on the Arab-Israeli conflict. But they never led to a rupture in relations.Although Saudi-American relations lack the shared affinities, values and mutual familiarity that are integral to the US-Israeli relationship, Saudi-US ties have been grounded in deeprooted common interests. For the US, this meant insuring a reliable supply of oil at bearable rates to fuel Western economies and maintaining Western security interests and regional stability, during the Cold War and since then; for Saudi Arabia, there was only one priority – regime survival and well-being.The author is a Principal Research Fellow at the Moshe Dayan Center for Middle Eastern and African Studies, Tel Aviv UniversityThe Nixon Doctrine of 1969 proclaimed Saudi Arabia to be one of the “regional influentials” vital for US security (the Shah’s Iran, ironically, was the other), and Saudi Arabia played a central facilitating role in the US-sponsored Afghan war against occupying Soviet forces.Nothing epitomized the US commitment to Saudi Arabia’s security better than Operations Desert Shield and Desert Storm in 1990-91.And over the decades, many layers of economic and defenserelated ties were built up, as Saudi petro-wealth was recycled through US companies eager to participate in Saudi Arabia’s massive development schemes. No less than 80,000 Saudi students are currently studying in US universities. To be sure, the fact that most of the 9-11 bombers were Saudi citizens caused major damage to the Saudis’ image in the US, but the relationship endured, and even deepened, as the Saudis eagerly assisted the US in its “war on terror” against al-Qaeda.Saudi Arabia’s vulnerability to external threats has been its enduring concern. Traditionally, Riyadh preferred quiet diplomacy, alliance-building and working in the shadows, while avoiding direct confrontation with stronger countries. In recent years, however, it has become more assertive. In the Arab-Israeli arena, it spearheaded the Arab Peace Initiative; during the 2006 Second Lebanon War, it cast much of the blame on Hezbollah and its Iranian patron. And in the Arab Spring upheavals, it led the Gulf Cooperation Council’s intervention in support of Bahrain’s crackdown on opposition Shi’ite protests, shepherded the ousting of Yemen’s embattled president, legitimized, via the Arab League, the NATO-led overthrow of Libya’s Qaddafi and, finally, supported the Sunni-led rebellion against the Assad regime in Syria.Throughout these upheavals, Riyadh has repeatedly struggled to make sense of US president Barack Obama’s policy on the Middle East.Washington’s abandonment of Egypt’s Hosni Mubarak, a longtime ally, stunned and shocked; Saudi intervention in Bahrain came directly after the US had called on the regime to engage in a dialogue with the opposition protesters; it was stunned again by Obama’s 11th-hour pullback from a military strike against Syria in favor of a deal with Russia to confiscate Syria’s chemical weapons.The Saudi press and some Saudi officials have been scathing in their criticism of America’s failure to act in Syria. For the Saudis, it constituted a victory for President Bashar Assad and his patron in Tehran, whose support has been crucial to his survival. In protest, Riyadh turned down a seat on the UN Security Council, calling the body unable to fulfill its mission of ensuring peace and security. And now, with the US reaching a diplomatic agreement with Iran on its nuclear program, Saudi Arabia looks on apprehensively, fearing that the renewal of a US-Iranian relationship will come at its expense, and without regard for its interests.Does it have options or leverage? One report spoke of plans to attain nuclear weapons capability via Pakistan. Another option was to initiate a nuclear enrichment program to match Iran’s. Manipulating oil pricing and production, offering lucrative contracts to non-US companies, and promoting greater militancy on the Palestinian-Israeli front are other possibilities. Presumably, there is disagreement within the Saudi hierarchy about where things are headed, how much its US ally can be trusted, and how much distance Riyadh should put between it and Washington.Although the ultimate Saudi nightmare – an Iranian-American “grand bargain,” which would confirm Iran’s preeminence in the region – is not in the cards, Saudi-US relations may be entering into uncharted waters.