SPREADING THE ISLAMIC REVOLUTION. Zeal of Iran's revolution persists, though early euphoria ebbs

Iran is big into advertising its revolution. A former rent-a-car stall at Tehran's airport is now an Islamic Propagation Office. Street posters remind Iranians of Islamic ``duties,'' such as liberating Jerusalem and confronting the United States. Whole walls at Tehran University are covered by portraits of the nation's top theocrats. Even hotel elevator billboards, once reserved for restaurant menus, show fatigue-clad children carrying pictures of Ayatollah Ruhollah Khomeini.

Eight years after Ayatollah Khomeini's return from exile to replace the Shah, many posters are a bit faded and frayed. But the impetus behind the creation of the Islamic Republic appears far from waning, diplomats and analysts here say.

An unusual blend of factors - third-world revolutionary zeal, the Shiite Islamic religion and Persian nationalism - has helped Iran's defiant and often arrogant revolution maintain its momentum. And a crucial fourth variable, the seven-year war with Iraq, may have inadvertently helped secure its immediate future.

First, the sustained passion behind the revolution stems as much from its broader vision as from its attempt to overhaul local politics. A sign in high black letters on Tehran's airport terminal quotes Khomeini, ``We are with all the innocents of the world,'' reflecting the revolution's self-perceived mission on behalf of the more than 80 third-world nations, not Muslims alone.

As parliamentary Speaker Hashemi Rafsanjani said last month, ``For third-world countries, the `have-nots,' our resistance to communism, imperialism, and capitalism is reason for hope.'' The lofty focus is similar in some ways to early socialists' dreams of ``liberating'' the world's proletariat.

Iran's specific aim is to be the vanguard of a new bloc of nations capable of defying both superpowers as well as conventional capitalist or socialist ideologies in favor of indigenous systems and values. The feeling that much more is at stake in Iran's political upheaval has provided added incentives for already zealous supporters.

Public expectations have also been lowered by the Gulf war. Iraq invaded Iran only 20 months after the Shah's ouster, forcing Tehran to divert resources when the revolution was in its infancy. Public grumbling is now often related more to war hardships than to the revolution's impact, with much of the anger directed at Baghdad rather than Tehran.

Second, the Shia Muslims (which rule Iran) have been on the defensive for 13 centuries, since the schism that lead to their early break from the mainstream Sunni sect that either rules or is the majority - usually both - in all other Muslim Middle East nations. That attitude is reflected in the liberal usage of words such as ``oppressed'' and ``downtrodden'' in so many of Tehran's posters. The sense of having some control over their national destiny and also being able to live according to the deep tenets of their faith - both for the first time in centuries - is a potent combination, diplomats say. Tens of thousands have been ``martyred'' in the war to defend those rights, as evident in black-bordered placards of young men's faces on bus windows, shop awnings, and home fences.

The war also brings out Iranian's religiosity. It technically erupted over rival claims to the strategic Shatt al Arab waterway. But Iran's current determination to see it through is also tied to longstanding tensions with the Muslim world's Sunni majority. Iraq epitomizes that struggle because it is ruled by a secular and Sunni regime, but its population is 60 percent Shiite.

Third, more than two milleniums of civilization have made Persians a notoriously proud and fiercely nationalistic people. Many like to point out their ethnic and historic distinctions from the Arab world. But Iran's Islamic history has included invasions by Arabs, Turks, Mongols, and Afghanis, and occupation by both Britain and the Soviet Union - all seen as challenging the Persian identity. Salteh, or foreign domination, is a highly charged concept in Iran.

The more recent alliance with - or, as many Iranians see it, subjugation to - the US further compromised that identity. In the late 1960s and '70s, a huge rug with the face of former President Kennedy greeted shoppers at Tehran's famous bazaar. A primary goal of the revolution was to restore dignity and independence from outside influence. A rug with Khomeini's face now hangs from the bazaar's high rafters.

Perhaps ironically, Iraq's 1980 offensive, designed ultimately to topple the then-insecure theocracy, actually helped the ruling mullahs consolidate support around an issue all Iranians initially backed - Iran's ability to determine its own future. The revolution and nationalism thus became inseparable.

Diplomats and political observers agree that the revolution still has a long way to go, particularly on economic issues, and that the initial public euphoria has ebbed. Yet the consensus is that this confluence of factors means that the revolution is far from running out of steam, and that the Islamic Republic is likely to survive for the forseeable future.

Robin Wright is a senior associate at the Carnegie Endowment for International Peace.