Saudi Arabia has undergone a remarkable political rebirth in the past few months, emerging as the Middle East’s most assertive Arab power. Until recently, various internal and international pressures constrained the kingdom’s ability to pursue its interests effectively. Deadly Al-Qaeda-inspired violence, an emboldened domestic reform lobby and the ratcheting up of post-9/11 anti-Saudi hysteria in the United States forced Riyadh to direct its political energies inward. Even though many of these pressures remain, the kingdom feels increasingly confident (warranted or not) in its ability to manage, co-opt or deflect them. It remains to be seen if Saudi assertiveness is tantamount to effectiveness. Many questions remain. It is unclear if the kingdom is actually containing the main forces, most notably sectarianism, threatening to destabilize the Middle East, or unleashing them. Saudi Arabia’s current muscular diplomacy, immersing itself in crises from Lebanon to Palestine to Iran, is driven by a sense of urgency. Iraq’s descent into bloody civil war and the potential for a jihadist spillover effect from Iraq into Saudi Arabia have led to heightened security measures. But Riyadh’s main fear is the specter of Iranian hegemony and the political empowerment of long-oppressed Shiite communities across the region. As Gregory Gause has recently noted, Saudi Arabia’s immediate objective is to ensure that the balance of power in the region does not tip too far in Iran’s direction. This is no small task. Iran appears to have emerged, so far at least, as the main victor from the US-led war to topple Saddam Hussein. In addition, in spite of international opprobrium, Iran has also successfully thwarted efforts to halt its alleged development of nuclear weapons, portending a potentially monumental shift in not only its military capacity, but in its ability to project its political will throughout the Middle East and Central Asia. Even absent the bomb, Iran’s power is being felt beyond Iraq and the Persian Gulf. Tehran scored an important victory last summer when the Iranian-supported Hezbollah effectively resisted Israel’s military push into southern Lebanon. The kingdom’s most recent diplomatic efforts should be seen as an attempt not only to reassert itself as a major player across the region, but also as an attempt to carve out anew spheres of influence for itself at the expense of Iran. It is unlikely that Saudi Arabia views the contest between itself and Iran today as solely driven by sectarian difference. But Riyadh also understands the power that sectarian anxieties possess and that it can leverage anti-Shiism in its favor with Sunnis across the Middle East if need be. While Saudi leaders are not openly fomenting sectarian conflict, they are hardly renouncing it, mostly because sectarianism has proven an effective political instrument in the past. In the 1980s, Saudi Arabia and Iran wielded and politicized Islam to great effect against one another, but also at great cost. While Saudi Arabia directed considerable energy to warding off the Soviet threat in Afghanistan, it also undertook and oversaw the complete vilification of Iran, Ayatollah Ruhollah Khomeini and Shiism more generally by inculcating the kingdom’s schools, religious institutions, and the public sphere with anti-Shiite vitriol. Anti-Shiism and anti-Shiite discrimination have, of course, always been present in Saudi Arabia. But the legacy of the 1980s is that political anti-Shiism remains a powerful impulse inside and outside the kingdom. The Iraq war and the Shiite ascendancy there have rekindled some of the most vituperative sentiment. Saudi Arabia’s leaders have been especially reluctant to rein in sectarian fulmination at home, where powerful clerics have become increasingly strident in denouncing Shiites across the Middle East. Some of the most prominent non-official religious voices in Saudi Arabia, including Saffar Al-Hawali, Nasr Al-Omar, and Abdullah bin Jibreen, have clamored for anti-Shiite violence in Iraq and elsewhere. Several dozen Saudi clerics along with some counterparts in Iraq circulated a petition in December 2006 inciting the intensification rather than the amelioration of sectarian violence. Riyadh has remained silent. The kingdom has made matters worse by cracking down on the kingdom’s own Shiites in various ways, including suppressing Shiite cultural activities, harassing community leaders, interrupting the observation of religious rituals, and even arresting activists. The new official anti-Shiism marks a sudden reversal and stands in stark contrast to efforts led by then Crown Prince Abdullah just a few years ago that seemed aimed at promoting tolerance. Sectarian patterns in Saudi Arabia provide a clue for how the kingdom might manage the issue at the regional level should tensions between it and Iran worsen. But even if Saudi leaders avoid making their struggle with Iran about sectarian difference, it will be difficult to convince publics across the region that the struggle is about anything else. With the unbounded reach of the new media, including the sophisticated web presence of many of Saudi Arabia’ most fulsome religious figures, it is unlikely that Saudi Arabia’s attempts to confront Iran and control sectarianism are sustainable. Toby Jonesis a Mellon post-doctoral fellow in the history department at Swarthmore College. As of the fall 2007, he will be assistant professor of history at Rutgers University. This commentary first appeared at bitterlemons-international.org, an online newsletter.