Athens — Three years after Iran's Islamic revolution swept Ayatollah Khomeini and his fundamentalist mullahs into power, the regime's reins are still held by the turbaned spiritual leader -- much to the surprise of his critics.
As early as March 1979 one Iranian told this correspondent that the ''regime won't last six months.'' Another Iranian who had become disillusioned with the revolution said about the same time it would ''take about two years for the people to get tired of the mullahs and perhaps another three years before they can overthrow them in a second revolution.''
How then has Ayatollah Khomeini weathered the three-year economic and political storm stirred up by the revolution?
Among those with an explanation to offer is Haqiqat Nader (his nom de plume) an Iranian professor of international affairs who has been working in Paris with the groups opposing the regime.
Speaking to this correspondent in Athens recently, Dr. Nader said ''two major forces keep Khomeini floating.''
One is the ''brutal force'' he employs. ''Khomeini has really demonstrated that he has no mercy whatever. The nature of the opposition does not make any difference. Force is a very powerful deterrent,'' Dr. Nader says. He disagrees with Amnesty International's estimate of nearly 4,000 people executed by the regime. ''I feel the figure is several times higher,'' Nader says.
The other reason why the regime has not come down ''is that the opposition forces have not been united,'' according to Nader. This includes the civilians and the military groups. ''There are many military officers trying to overthrow the regime. They are made up of hundreds of Army officers who have escaped and are now trying to contact friends back home.''
Today, says Nader, the opposition in exile is ''so certain the regime will collapse soon that we are working very hard to prepare short-term economic and political programs for Iran so that we will not be unprepared.''
Critics of the Khomeini rule believe it is in serious trouble on four counts:
1. Although Khomeini is a cohesive force keeping the regime together, the ruling mullahs are highly repressive.
2. The regime is practically bankrupt. It has hardly any earnings, either local or from foreign oil sales.
3. There is no cohesion in planning, and an increasing number of Iranians are becoming alienated.
4. The regime is internationally isolated. Apart from the dubious support of Syria, Libya, and Algeria it appears to be without international friends.
If the regime falls, analysts feel it will probably come about through a popular uprising, with some assistance perhaps from armed groups, including military dissidents, and the various guerrilla organizations now operating against the Ayatollah.
Opponents hope that by then the opposition will have become more united and will help accelerate the process. This, at any rate, is what former Premier Ali Amini has been working toward.
After talking to various Iranian groups outside Iran for more than a year, Dr. Amini called a press conference in Paris Jan. 19 to announce the formation of the ''Iran Liberation Front.'' He has not been able to bring such bitter enemies as former Prime Minister Shahpour Bakhtiar and former President Abolhassan Bani-Sadr together, but in general Dr. Amini has got the opposition groups to agree to a seven-point basic program for toppling the regime.
The idea is that once the regime is toppled the opposition would form a governing body to take over. The new body would be made up of basically ''the various forces that believe in democracy, freedom, and the national independence of Iran.''
The intention is to restore law and order in the country and then determine through popular elections the kind of government Iran would have.
No group or force is being left out of the Iran Liberation Front. It includes the late Shah's son, Reza Pahlavi who now calls himself ''Reza II.'' But the Front insists it would be for the people to decide whether Iran is to return to a monarchy or set up a new republican regime.
''This may not be decided through a referendum,'' Dr. Nader says, but rather by ''some form of constituent assembly.''
Nader hints there are also groups inside Iran working with the Iran Liberation Movement, ''but no names can be mentioned for security reasons. . . . We have been in contact with major elements in Iran.''
This includes a large number of religious leaders. ''We feel the (post-Khomeini) regime would have the support of religious leaders'' but in general the new regime would be secular. ''Religion would be kept out of politics.''
[Tehran Radio, monitored by Reuters reported Feb. 8 the top guerrilla leader fighting Ayatollah Khomeini's regime was killed in a shoot-out with revolutionary guards in Tehran. The radio said Mussa Kheyyabani, operational commander of the radical Mujahideen-e Khalq movement, died alongside other members of his central committee.]