democracy vs. tyranny -- meets the dictates of Middle Eastern geography. Whereas Iraq, Syria, Saudi Arabia and other Arab states are puzzle pieces carved out of featureless desert, with no venerable traditions of statehood, the roots of a great Persian power occupying the Iranian plateau date to the Achaemenid, Parthian and Sassanid empires. With nearly 70 million people occupying the tableland between the oil-rich Caspian Sea and the oil-rich Persian Gulf, Iran is the Muslim world's universal joint. Iranian power, both soft and hard, is felt from the Mediterranean to the Indus. Indeed, Iran's influence in southern Lebanon and Gaza is part of a historical tradition of empire and Shiite rule. By puncturing the legitimacy of the clerical authority, the demonstrations in Tehran and other cities have the capacity to herald a new era in Middle Eastern and Central Asian politics. Iran's governing institutions, however illiberal their current intent, are structurally sounder than most in the Arab world. When the shah was toppled, anarchy did not ensue: Within weeks, a Shiite bureaucratic apparatus filled the void. That sophisticated network reflected not just religion but also Iranian high culture. The Iran of the ayatollahs was never a one-dimensional tyranny such as Saddam Hussein's Iraq; it is a complex system with an elected parliament and chief executive. Likewise, Iran's democracy movement is strikingly Western in its organizational discipline and its urbane use of technology. In terms of development, Iran is much closer to Turkey than to Syria or Iraq. While the latter two live with the possibility of implosion, Iran has an internal coherence that allows it to bear down hard on its neighbors. In the future, a democratic Iran could be, in a benevolent sense, as influential in Baghdad as the murder squads of a theocratic Iran have been in a malignant sense. Iran is so central to the fate of the Middle East that even a partial shift in regime behavior -- an added degree of nuance in its approach to Iraq, Lebanon, Israel or the United States -- could dramatically affect the region. Just as a radical Iranian leader can energize the 'Arab street,' an Iranian reformer can energize the emerging but curiously opaque Arab bourgeoisie. This is why the depiction of presidential candidate Mir Hossein Mousavi as but another radical, albeit with a kinder, gentler exterior than President Mahmoud Ahmadinejad, completely misses the point. As in the former Soviet Union, change in Iran can come only from the inside; only an insider, be it a Mousavi or a Mikhail Gorbachev, has the necessary bona fides to allow daylight into the system, exposing its flaws. Only a staunch supporter of the Islamic Republic such as Mousavi would have been trusted to campaign at all, even as he is now leading a democratic movement that has already undermined the Brezhnevite clerical regime. It is unfinished business of the Cold War that we have been witnessing the past few days. The Iranian struggle for democracy is now as central to our foreign policy as that for democracy in Eastern Europe in the 1980s. It is crucial that we reflect on an original goal of regime change in Iraq. Anyone who supported the war must have known that toppling Saddam Hussein, a Sunni Arab -- whether it resulted in stable democracy, benign dictatorship or sheer chaos -- would strengthen the Shiite hand in the region. This was not seen as necessarily bad. The Sept. 11 terrorists had emanated from the rebellious sub-states of the sclerotic Sunni dictatorships of Egypt and Saudi Arabia, whose arrogance and aversion to reform had to be allayed by readjusting the regional balance of power in favor of Shiite Iran. It was hoped that Iran would undergo its own upheaval were Iraq to change. Had the occupation of Iraq been carried out in a more competent manner, this scenario might have unfolded faster and more transparently. Nevertheless, it is happening. And not only is Iran in the throes of democratic upheaval, but Egypt and Saudi Arabia have both been quietly reforming apace. In recent years, an anti-Iranian alliance of sorts has emerged of Israel and those tired Sunni Arab dictatorships. Throughout Iranian history, dating to Cyrus the Great, Jews and Persians have often had an alliance against the mass of Arabs and other peoples that border Iran to the west and south. In brief visits to Iran, I have sensed a greater aversion to Saudi Arabia, for instance, than to Israel. A virulent hatred of Jews may turn out to have been an attribute of the clerical regime, which won't outlive it, at least not to the same extent. The late Shah Mohammad Reza Pahlavi did, in fact, maintain an implicit alliance with Israel, and future Iranian leaders must look at the world from the same geographical position as he did, without the baggage of Third World radicalism with which the mullahs had been indoctrinated early in the Khomeini period. But a future behind-the-scenes battle between Sunni Arabs and Shiite Iranians for a silent strategic contract with Israel can be effected only if the United States exerts strong pressure on Israel to cede West Bank territory. Never has there been a better time to push for an Israeli-Palestinian peace settlement, even if it requires the collapse of today's Israeli coalition in the process. The Middle East has entered a period of deep flux, to be further amplified by elections in Iraq later this year and the seating of a pro-Western government in Lebanon. Because of its central geographic and demographic position astride the energy-rich Middle East -- not to mention the attractive force of Persian culture seeping far into Central Asia -- Iran, ironically, has a better chance to dominate the region under dynamic democratic rule than it has ever had under its benighted clerisy. And that could be very good for the United States. Robert D. Kaplan is a senior fellow at the Center for a New American Security and a national correspondent for The Atlantic. 