Quotes of the Day

The crisis was Bahrain's, but the 100 giant army tanks patrolling the island kingdom's capital, Manama, boasted two flags — Bahraini and Saudi Arabian. And the presence of the latter was a metaphorical salvo at an unseen combatant: Iran, the alleged patron of Bahrain's Shi'ites who were in the middle of an uprising against the country's minority Sunni ruling class (Iran has not publicly supported the Bahraini opposition). Quelling the Shi'ite rebellion in Bahrain was a proxy war between the two oil powers, the closest Riyadh and Tehran have come to any sort of violent confrontation in their burgeoning rivalry. Diplomatic spats have come up, over Lebanon and Syria, for example. But all the bile had been behind closed doors until this week, when the U.S. alleged that an Iranian plot had as its target Adel al-Jubeir, the Saudi ambassador to Washington and a trusted adviser to King Abdullah of Saudi Arabia.

The supposed plot "is something new," says Jane Kinninmont, a Middle East researcher at London think tank Chatham House who follows Bahrain and events in the Gulf. If true, "it will seriously raise Iranian-Saudi tensions." It's a deviation in a conflict that is generally relegated to rhetoric and diplomatic gestures, not concrete action. Says Salman Shaikh, director of the Brookings Doha Center: "There are long-simmering tensions between the Saudis and other Gulf states, and Iran. There's a deep suspicion."

The tension between Riyadh and Tehran "has been a media[-fueled] war of words between the two countries, although until now, nothing more than that," says Simon Henderson, head of the Gulf program at the Washington Institute for Near East Policy. News of the plot against al-Jubeir is "very concerning. I think they'll be widely believed in the Gulf because people there already regard Iran as aggressive and devious, and are predisposed to believe in Iran's strength and have a deep anxiety about [encountering] it."

Until the two Iraq wars involving the U.S., Saudi Arabia had been happy to let Iran throw its weight around. But the Shi'ite ascendancy in what was once secular, though Sunni-leaning, Baghdad has thrown the balance of power in the Gulf out of whack. Even so, Riyadh had taken a quiet approach to its Shi'ite rival. "This is a classic cold-war game where you do things under the radar, you don't try to be too public. And we're dealing with the Saudis, who don't do things overtly. They're behind-the-scenes people," says Barak Barfi, a fellow at the New America Foundation who follows the conflict and has spent time in Bahrain. If the Saudis decide to get even for the assassination plot, says Barfi, "they won't retaliate with a similar plot, but they're going to spread money out to allies to counterweight the Iranians and their surrogates."

Barfi says that with this latest incident, the region might have to take sides overtly. "You'll start to see green and white countries on a map of the region," he says, "One color loyal to Iran, the other color loyal to Saudi." He says the Saudis' hatred for Iran runs so deep that there is even a remote possibility Riyadh might even take part in behind-the-scenes talks with a country it despises, Israel, because the Saudis see the Jewish state as a powerful counterweight to Tehran — the bête noire of Israel.

Foiling the alleged plot against al-Jubeir could strengthen what has been a weakening friendship between the U.S. and Saudi Arabia. "They've been drifting apart," Shaikh says of Riyadh and Washington, "but this is an issue they've been working on at different ends that could bring them together." The Saudis could urge the U.S. to take a tougher line in its already hard-line dealings with Iran. That would not help an already volatile region. "The last thing the Middle East needs in the wake of the instabilities caused by the Arab Spring is a renewed Iranian-Saudi proxy war," says Barfi. But, he adds, "this is exactly what we should expect."

As for the last proxy war, the crackdown is still going on in Bahrain. Though Saudi tanks have disappeared from downtown Manama, there are still nightly clashes in Shi'ite neighborhoods between opposition activists and Bahraini security forces. During spring conflict, the country's Sunni-run television channel Bahrain TV, which served as a chief instigator of anti-Shi'ite propaganda, fueled rumor after rumor that the Iranians were supporting the Shi'ite opposition, even alleging that Tehran had sent boats filled with weapons to Bahrain. The tension between the two countries "has always been fueled by sectarianism," Shaikh says. In the past month, Bahraini rulers have continued to repress dissent, for example, upholding the life sentences imposed on activists and the conviction of medical personnel accused of assisting and tending to injured protesters. "The Saudis will pressure their allies in Bahrain to cease offering any concessions to the Shi'a opposition, which it falsely links to Iran," says Barfi. If things get worse between Riyadh and Tehran, so will the plight of Bahrain's Shi'ites.

• Karen Leigh
• Riyadh flexed its muscles in Bahrain when it saw an alleged threat from Iran there. How will it respond to the alleged plot to kill its ambassador to the U.S.?