WASHINGTON – It means something in foreign policy circles when realists and idealists converge on a policy – as they are beginning to do on Iran.

Realists – think Richard Nixon and Henry Kissinger – assert that only the external behavior of a regime is of direct concern to America; its habits of repression matter little to the national interest. Idealists – think Ronald Reagan and George W. Bush – believe that the internal nature of a regime eventually determines its external behavior; a government that represses its people is more likely to be aggressive and destabilizing, so American interests are served by the spread of democratic ideals. Somewhere in the compromise between these views, U.S. foreign policy is formed.

I consider myself a foreign policy idealist. My former colleague in the Bush administration, Richard Haass – now president of the Council on Foreign Relations – describes himself as a “card-carrying realist.” But Haass might also be called a principled realist. He believes that the diplomatic engagement of repressive regimes must be justified by outcomes. And the benefits of engagement with the Iranian regime have been slim.

In a recent Newsweek essay, Haass argues that Iranian nuclear ambitions are unmasked, that nuclear negotiations have failed, that the Green Revolution is more viable than many first thought, and that promoting “political change” in Iran – regime change – is a now a strategic opportunity. This change would not solve every problem between America and Iran – some in the Iranian opposition support their country’s nuclear ambitions – but a more representative regime would certainly be less aggressive, less tied to terrorism and more open to international influence.

For some Americans, the idea of regime change is tainted by the Iraqi invasion and occupation. But there is also the model of South African regime change, overturning apartheid with massive international pressure, and Polish regime change, aided by covert American support for unions and democratic resistance.

No one argues that the Iraq model should apply to Iran. But is Iran ripe for the South African or Polish approaches? Part of the answer may come on Feb. 11 – the anniversary of Iran’s Islamic revolution – when the democratic resistance has called for another round of mass protests.

There are signs of a revolutionary instability in Iran. The Green Revolution has mobilized support beyond Tehran and beyond the middle class. Fissures have emerged within Iran’s political and clerical elites. Before his recent death, Grand Ayatollah Hossein Ali Montazeri attacked Iran’s “military regime” and criticized “show trials” that have “given cause to the entire world to mock Islamic justice.”

So far, however, the instruments of state repression – the Revolutionary Guard and their brutal militias – have held tough. Iranian opposition leaders seem more accidental and reactive than heroic and visionary, more Boris Yeltsin than Lech Walesa. The Green Revolution has not yet built effective cooperation with Iran’s oppressed minorities: Sunnis, Kurds, Balochs, Azeris. Anti-government demonstrators have often been heroic, but their tactics have not expanded to include strikes and other methods to paralyze the regime.

Mohsen Sazegara – a resistance leader in exile, who was once a press aide to the regime’s founder Ayatollah Ruhollah Khomeini – told me that the Green Revolution “needs more time” to improve the quality of its organization, to gain “more depth of knowledge of nonviolent methods” and to “fill the gaps in solidarity” among various anti-government groups. “But the most important gap,” he insists, “is between the knowledge of the nation and the ignorance of the regime.” A revolution often seems incredible – right before it becomes inevitable.

American leverage over events in Iran is limited, including: sanctions that try to jolt the Iranian economy or that focus on the Revolutionary Guard; technical aid for activists to circumvent Internet censorship; covert financial assistance to organize anti-government activities; and the deployment of missile defenses in the region. But most important, the Obama administration must cross a mental line – from merely criticizing human rights abuses to creatively encouraging political change.

“When fighting an authoritarian regime,” says Sazegara, “one of their strategies is to perpetuate the notion that you have no power, that you are alone, that nobody can help you. It is how they try to control and paralyze a nation.”

On Feb. 11 and beyond, the people of Iran, seeking their own regime change, need to know they are not alone. Such idealism is now the only realistic course.

© 2010, Washington Post Writers Group