A long-brewing power struggle recently burst into public view over Iranian President Mahmoud Ahmadinejad's decision last month to dismiss Intelligence Minister Heydar Moslehi. The ensuing power struggle between Ahmadinejad and Supreme Leader Ali Khamenei has left the Iranian president deeply weakened and revealed many useful lessons about the closed and convoluted political workings of the Islamic Republic. On the surface, the battle appeared to be over when Ahmadinejad backed down. But there are deeper issues at stake which remain far from resolved. When Khamenei gave the president an ultimatum to reinstate the minister or resign, the supreme leader was not only preserving his own power -- the supreme leader has final say over government affairs -- but that of the entire clerical establishment.

The real fight was not about cabinet ministers. It was part of a test of wills between the Ahmadinejad loyalists, especially those in the Islamic Revolutionary Guard Corps (IRGC), and the ruling clerical establishment over ideology, religion, the survivability of the Islamic Republic, and Iran's influence in Arab states now in transition. Khamenei appeared to believe that the cocky, alarmist Ahmadinejad, who in recent months had been boldly advancing an Iran with minimal clerical influence run by the IRGC and inspired by Iranian nationalism, not Iranian revolutionary Islamism, had to be slapped down. Otherwise, the Islamic Republic, as it has existed since the 1979 revolution, risked extinction. It might seem counterintuitive, but Khamenei's survival and that of the clerical system is in the West's interest. The alternative -- a highly militarized state run by the Revolutionary Guards -- would be much worse.

Since his election to a first term in 2005, Ahmadinejad had carefully courted Khamenei, his most powerful advocate in the volatile world of Iranian politics. In June 2009, in a rare but highly symbolic moment, Ahmadinejad became the first president in the Islamic Republic to kiss the hands of the supreme leader during his second inauguration ceremony. But no longer. Ahmadinejad embarked on another new trail by becoming the first president in the republic to publicly disobey the supreme leader. Angered by Khamenei's interference in the management of his cabinet, the president staged a boycott and did not show up for work for 11 days.

Khamenei and other powerful figures have clearly come to believe the president poses a very real threat to the system. This has prompted even many of Ahmadinejad's ardent supporters to side with Khamenei. Reactionary cleric Mesbah Yazdi, a longtime mentor of the president, turned against him and criticized the president for challenging supreme clerical rule, the foundation of the Islamic political system. "Some people introduce themselves as supporters of velyat (supreme clerical rule), but in reality they act otherwise," Yazdi said. "The restoration of anti-clerical thinking could be the next great sedition in this country," he said, clearly demonstrating his fears of a plot to do away with, or at least weaken, Iran's political clergy. Other reactionary clerics have gone as far as to throw the president in with Iran's "enemies," a category usually reserved for Israel and the United States.

As much as Khamenei detests the United States, he will always prefer "soft power" to a military confrontation, whether it is with Israel, the United States, or regional rival Saudi Arabia. This is not the case for Ahmadinejad and his partisans inside the IRGC whose members have gained greatly in both political and economic influence. Ahmadinejad is still believed to have powerful supporters inside the Corps, despite comments made last week by Maj. Gen. Mohammad-Ali Jafari, the commander of the IRGC, warning the president to "stay away from deviant factions," a term used to refer to Ahmadinejad's chief of staff and close confidant, Esfandiar Rahim-Mashaie. Many high-ranking officers and the rank and file of the IRGC share Ahmadinejad's radical views and political ideology and have greatly benefited from his government's policies in the past six years. They will stop at little to provoke Israel and empower Iran's regional proxies, which include Syria, Hamas, and Hezbollah.

While the two factions have disagreed in the past on nuclear negotiations with the United Nations, their real differences revolve around the future direction of Iran's Islamic system, with the nuclear program only a proxy arena for waging those deeper political battles. The president's pretenses of reaching out to engage the United States and Western governments are solely to increase his power internally, with the hope that the power structure might change and Khamenei might be the last supreme leader.

Ahmadinejad and Mashaie, whom the president hopes will succeed him when his term expires in 2013, envision a future Iran devoid of Islamic orthodoxy. This attempt to take Iran in a new direction has prompted accusations from high-ranking clerics that Ahmadinejad and Mashaie are influenced by religious "deviants" who believe in supernatural powers and djinns, or spirits. In fact, in the past Mashaie has said he can interpret for himself the Islamic texts, such as the Quran, and does not need the clergy -- an enormous threat to the clerical establishment's claim to religious sanction for their hold on power. In response, Ayatollah Mesbah Yazdi told a group of IRGC officers and staff that, "In order to learn the religion, one must go to scholars of the religion and not to exorcists and monks. Which wise person would accept learning the faith from exorcists and monks instead of scholars of the faith?"

Not only would Ahmadinejad and Mashaie's vision lead to the marginalization of Iran's clerics, but it would also make it far less likely that Iran could exert influence in Egypt, Bahrain, Lebanon, Palestine and continue to call the shots in Iraq. Without the clerical establishment, Iran would have no religious or moral authority to interfere in these countries, where Iran seeks to extend its political influence in the name of Islam. This is definitely bad news for the United States and other Western governments, which worry that Iran will succeed in extending its influence in the Arab world, particularly after the Arab uprisings.

While this is a downside to Khamenei's triumph in the power struggle, his victory has preserved a system the West might not understand but one that so far remains somewhat predictable. Such is the state of affairs inside Iran's regime that Khamenei and the conservatives the United States once called "hard-liners" are now a safer bet than the wild card that is Ahmadinejad.

Geneive Abdo is the director of the Iran program at the National Security Network and the Century Foundation and the editor of insideIRAN.org. Arash Aramesh, a researcher for the program, contributed to the article.