The Iranian regime is one of the few remaining allies of the embattled Syrian President, Bashar al-Assad. For years, the United States has tried to sever the ties between the two countries, but the current crisis has only pushed them closer together.

Ayatollah Ali Khamenei, Iran's supreme leader, has made it clear that Tehran sees the uprising in Syria as a U.S. ploy: "In Syria, the hand of America and Israel is evident," he said on June 30. Meanwhile, he affirmed Iran's support for Assad, noting, "Wherever a movement is Islamic, populist, and anti-American, we support it."

Despite disagreements on other matters, the rest of the Iranian regime seems to concur with Khamenei about Syria. Iran's Islamic Revolutionary Guards Corps have characterized the Syrian uprising as a foreign conspiracy. And the parliament, which in recent years has competed for power with the guards, President Mahmoud Ahmadinejad, and the supreme leader, is also in lockstep. On August 8, after a trip to Cairo, Alaeddin Boroujerdi, the chairman of the Iranian parliament's Foreign Policy and National Security Committee, reiterated Khamenei's stand. "Having lost Egypt," he said, "the U.S. has targeted Syria."

For Iran, Assad's Syria is the front line of defense against the United States and Israel. Without his guaranteed loyalty, the second line of defense -- Hezbollah and Hamas -- would crumble. According to U.S. estimates, Hezbollah receives $100 million in supplies and weaponry per year from Tehran, which is transported through Syria. It would become all the more difficult to use Iran as a proxy against Israel if the Syrian borders were suddenly closed.

Moreover, the Iranian regime is particularly sympathetic because it views the Syrian uprising as similar in kind to the waves of protest that swept Iran in 2009 and 2010. Those protests, they have claimed, were a U.S.-backed attempt at regime change. The Syrian ones, the thinking goes, are a U.S. maneuver to destroy the Iran-Syria-Hezbollah axis -- the bedrock of Iran's power in the region. Speaking this spring, Ahmad Mousavi, Iran's former ambassador in Damascus, made this explicit: "Current events in Syria are designed by the foreign enemies and mark the second version of the sedition which took place in 2009 in Iran," he said. "The enemy is targeting the security and safety of Syria ... [The protestors] are foreign mercenaries, who get their message from the enemy and the Zionists."

It should not be surprising, then, that Iran has taken significant measures to keep Assad in power. According to U.S. officials, as of April Iran was providing the Syrian security services with weapons, surveillance equipment, and training. Earlier this month, Ankara intercepted an arms shipment headed from Tehran to Damascus -- the second such shipment it caught this summer.

The Iranian regime has also provided Assad with technology to monitor e-mail, cell phones, and social media. Iran developed these capabilities in the wake of the 2009 protests and spent millions of dollars establishing a "cyber army" to track down dissidents online. Iran's monitoring technology is believed to be among the most sophisticated in the world -- second, perhaps, only to China. Shortly after Iran shared its know-how with Syria this summer, Assad lifted restrictions on social networking Web sties, presumably to lure dissents out into the open.

In addition to sharing weapons and surveillance tools credible reports from Syrian refugees indicate that Tehran sent its own forces to Syria to quash the protests. A number of revolutionary guards from the elite Quds Force are also reported to be there, presumably to train Syrian forces. On May 18, the U.S. Treasury Department mentioned the role of the Quds Force directly, asserting that Mohsen Chizari, the Quds Force's third-in-command, was training the security services to fight against the protestors.

So far only one major Iranian voice has dared to question the Iranian regime's support of Assad. Grand Ayatollah Dastgheib, a member of the Assembly of Experts and a spiritual guide for Shiite Muslims, questioned Tehran's strategy during his weekly Koran interpretation session at the Qoba mosque in Shiraz on June 23. He emphasized that Iran's resources should be saved for Iranians and asked, "Where should the public wealth that could make this country one of the best in the world be spent? Should it be sent to Syria, so they can oppress the people?"

Iran's other major regional allies -- Turkey and Hamas -- have also been hesitant to follow Iran's lead. Iran values the improvement in its ties with Turkey that came with Recep Tayyip Erdogan's rise to power and wants Ankara to serve as a buttress to Iran's regional strategy, and even as an interlocutor with the United States. But as Erdogan became more critical of Assad this summer, Tehran soured on the relationship. Iranian officials even openly blamed Erdogan for the unrest, and promised consequences should he not recant. Similarly, over the last two months, Hamas officials refused to hold rallies in the Gaza Strip in support of Assad. According to officials, Tehran has since cut off funding to Hamas.

Assad's chances of staying in power are greater than were those of Tunisian President Zine el-Abidine Ben Ali, Egyptian President Hosni Mubarak, and Libyan leader Muammar al-Qaddafi. He may be forced to make some concessions to the protestors, but he still wields too much power to be removed from office completely. To date, there have been no significant defections within the Alawite-controlled military, which is key to his survival, and the Iranian-trained and supplied security forces have prevented the protests from reaching the levels of those in Tunisia, Egypt, and Libya. In Iran's view, much like the Tehran spring, the struggle for Syria is one of regime survival. Even if Assad should eventually fall, Iran will not stand idly by; Tehran will surely try to influence any successive government.