WASHINGTON -- In early 2005, the advance of freedom in the Middle East had an air of inevitability. Hundreds of thousands demonstrated in Beirut to demand an end to Syrian occupation. Eight and a half million Iraqis voted with purpled fingers. Even Egyptian President Hosni Mubarak permitted a multiparty election. People talked of an "Arab Spring."

By 2006, what had seemed inevitable was dismissed as incredible. Iraq had descended into civil strife, apparently aided by elections that reinforced sectarian divides. Voting in the Palestinian territories brought Hamas to power. Mubarak, the old angler, reeled back most of the freedoms he had granted.

Some American conservatives found Burkean lessons in the fading freedom agenda, asserting that democracy is a fragile flower that only grows in a rich cultural soil tended by Jeffersons and Hamiltons. Many liberals seemed relieved that President Bush didn't seem right after all, though this involved global setbacks for political liberalism. It may seem strange that anyone should feel a thrill of vindication when the ideals of their nation appear to falter. But let us judge not, that we be not judged.

Now spring is returning. January's local elections in Iraq favored secular nationalists instead of clerical parties. In Lebanon, Hezbollah was defeated in an open and vigorous vote. Kuwaiti women have been elected to parliament for the first time. And in Iran, brave women and men have demonstrated that democracy, not just nihilism, counts martyrs in the Muslim world.

If one lesson stands out from these years of bipolarity, it is this: Experts will overinterpret events to confirm pre-existing views. No snapshot in this complex historical process is the permanent picture. Every idealist will have his day; every realist will have his night.

But while the development of democracy in the Middle East is not linear, it is also not random. It moves in steps, but upward. Taken together -- a constitutional Iraqi democracy, a powerful reform movement in Iran, democratic achievements from the Gulf sheikdoms to Lebanon -- this is the greatest period of democratic progress in the history of the region. Given consistent outbreaks, it seems clear that the broader Middle East is not immune to the democratic infection. And there are reasons that the democracy agenda will remain central to American foreign policy, whatever the mood of the moment.

First, progress in the broader Middle East is not possible without economic and political reform. The total GDP of the resource-rich Middle East and North Africa (excluding Israel) is less than that of Italy. Average life expectancy in the region is 16 years shorter than in Israel. What political and social system could possibly reverse this slide? Military dictatorship, a la Saddam or Assad? Iranian theocracy, which now depends for its legitimacy on an unstable demagogue? There are no realistic alternatives to freedom for the recovery of regional prosperity and pride.

The reason is simple: Political and social systems that reward human creativity create wealth and lead to progress. Such progress is not fated by historical forces. Democracy is not inevitable like communism was said to be; it is inevitable like hope.

Second, the advance of freedom in the Middle East is America's best hope. Regimes that oppress their people are more likely to threaten their neighbors, support terrorist groups, feed anti-Americanism and anti-Semitism to distract from their failures, and seek weapons of mass destruction. Other democracies do not always do what we wish. But nations based on the consent of the governed are simply more peaceful than nations ruled by the whims of despots.

Of course there are challenges in promoting democracy -- how to best strengthen civil society, how to encourage not only elections but also constitutionalism, how to sequence reforms.

But the goal of democracy promotion is a consistent American commitment. It is the foreign policy consensus that emerged from World War II -- the bipartisan belief that America benefits from the expansion of free societies, free economies and a liberal trading order. And this belief led American presidents to proclaim the goal of universal freedom, even while occasionally dealing with dictators. Franklin Roosevelt sat with Stalin while defining four freedoms that apply "everywhere in the world." Ronald Reagan dealt with a Soviet leader even as he foresaw and hastened the downfall of the Soviet empire. Their democratic idealism did not prevent them from dealing with the devil; only from believing that the devils own the future.

Democracy promotion is difficult and reversible. It is also not new -- or optional.