With Ayatollah Ruhollah Khomeini finally back home after 14 years of exile, Iranians are beginning to wonder what lies ahead as the country enters yet another stage of its revolution.

Without waiting for the outcome of the power struggle between Prime Minister Shahpour Bakhtiar and Khomeini -- who appointed his own "prime minister" Monday to head a provisional Islamic government -- Iranians are drawing best-case and worst-case hypotheses.

Thoughtful Iranians realize major problems will remain even if Khomeini sweeps Bakhtiar aside with minimum turmoil and gets people back to work by the force of his presence.

The economy, despite the country's oil wealth, will require many months -- pessimists say even several years -- to get back on its feet. Massive loans, particularly from the United States, will be needed, even if economic priorities are reordered and the shah's grandiose plans, including arms purchases and nuclear programs, are abandoned.

What's more, foreign experts and technicians, many of them American, would have to be invited back, a step that will have to be preceded by a drop in the wave of xenophobia sweeping the country.

Politically, the Islamic movement would have to keep its unity and the nascent left would have to bide its time, while a third major actor, the army, remains quiescent, fearing untoward steps would mean the end of its sorely tried unity.

Perhaps most important of all, the middle class will have to dig in and stay. It was the defection of technicians and managers, the movers and shakers, that sealed the shah's fate.

If they leave it could well seal the fate of those who hope the new Iran will be in earthly and spiritual paradise.

The worst-case hypothesis -- a complete social, political and economical unraveling -- could well start with a middle class exodus. The upper middle class already has cleared out in great numbers.

If turmoil continues, then there is little hope of keeping the army together. Local leaders could well take over various parts of the country leading to armed insurrection and civil war with an impact that could easily spill over sensitive borders.

Even if Iran holds together geographically, what about the dangers from the political left?.

For months, Marxists have been holding political propaganda sessions in factories and offices shut down by a general strike. They are finding it easy to radicalize workers who until a few months ago had never dared to think in political terms because secret police masquerading as trade union officials were always present.

The Marxists may now be strong enough to disrupt Khomeini's hopes of social harmony.

Revolutions, it has been said, devour their young. For those with a sense of history, it is difficult to avoid the impression that Iran's revolution is consuming its children in textbook fashion.

Is this just an uprising against absolutism, as in the French Revolution, or does Iran more closely resemble the class struggle of the Russian Revolution in 1917?

Will Bakhtiar, the prime minister who arranged the monarch's much-delayed, but bloodless exit, be replaced by yet another leader? So much seems tied to the intransigent personality of Khomeini himself. And at 78, he is an old man.

Does Khomeini's dream of an Islamic republic -- a return to the first days of Islam 1,300 years ago -- apply to a quintessential example of a society in transition, a society that went awry because of the shah's forced pace of modernization?

Some hopeful Middle East hands are convinced that no matter what Islamic plans he has for Iran, the country is set inexorably on the long road to democracy.

Ataturk started the democratization process more than 50 years ago in neighboring Turkey and the seemingly constant political convulsions there indicate that it is a rocky road indeed.

More pessimistic analysts are convinced that the strong-man tradition is so firmly entrenched that sooner or later another shah-like father figure will emerge, although only ultraloyalists think it will be the shah himself.

Whatever happens, both pessimists and optimists agree that the best course for the United States is to keep its hands off a country where for too long Washington's policy was considered the main prop of a leader who is now discredited.