The Revolutionary Guard looking our way at the entrance of the Iranian parliament late last month was quite decided in his opinion: "But of course, I want Reagan to win," he said leaning his new rifle against the railing.

"You see he has not the subtlety of Mr. Carter, who lets Saddam [Hussein, president of Iraq] do his work for him. No, he'll attack us and by doing so unify us, so that our nation can defeat the Americans and once and for all kill their imperialism." He added, in a reference to Iranian ruler Ayatollah Ruhollah Khomeini, "Anyway the imam has said the Carter will lose."

He was no more than 20 years old. The beard, the gray uniform, the gym shoes were all typical of the Revolutionary Guards, the defenders of the revolution. He was deadly serious in his analysis even when confronted by the skeptical glances of foreign correspondents covering the parliament's debate on the conditions for the release of the American hostages.

Many in Iran felt the same in the late days of October, as the United States neared its presidential election and the parliament in Tehran discussed under what conditions the 52 American hostages should be freed.

The difficulties created for Iran by its war with Iraq and the potential dangers of a Ronald Reagan presidency had convinced even those staunch supporters of the embassy seizure that they had to act at once to avoid the kind of scenario that the overzealous Revolutionary Guards had been describing.

Some of the militant Iranian legislators, such as Mohammed Montazeri and Ayatollah Sadegh Khalkhali, were convinced by Nov. 2 that they had fulfilled their objectives.

When, on the morning of Nov. 5, it was clear that Reagan had won easily, the first reaction here was deathly silence.

"We have always said it makes no difference -- Reagan or Carter -- they are both capitalist puppets," was the official statement from a spokesman in the prime minister's office.

But behind that official line, dismay and complete surprise were obvious. The fact that the American voters, after all the false hopes of the past year, were not to be influenced by their manipulations of the hostage issue had never occurred to the Islamic fundamentalists controlling the corridors of power in Iran. The shock was evident in their stammered murmurs of "no comment."

Just two days before the election, Montazeri was brimming with optimism. "We are now in a position of strength," he said. "The matter is resolved as far as we are concerned.It's up to Carter now."

He made his reasons very obvious when, in an interview, he talked of the American-made weapons and spare parts Iran has bought but the United States has refused to deliver because of the seizure of the hostages.

"We need the weapons, and we need them badly," he said. "Apart from that, while both the Democrats and the Republicans are fascists and Zionists, the Republicans are without doubt the more fascist of the two."

After Reagan's election, it was left to the so-called moderates, the supporters of President Abol Bani-Sadr, to articulate the disappointment.

Ali Reza Nobari, the youthful president of the central bank said: "I admit that on the level of foreign diplomacy we have failed completely. We could have had a direct and very positive influence on the U.S. presidential elections, but alas due to our own failings we let the chance slip by.

"In the first instance the hostage question helped Carter. It allowed him to concentrate on the nationalistic sentiments revived by the embassy occupation. But we never gave Carter the chance to resolve the question, enabling Reagan to continue preying on that nationalistic fervor.

"His election means a direct change in the psychology of the American people . . . What we have done -- consciously or unconsciously -- is play a part in changing that [Carter administration] psychology of nonintervention to an aggressive, sort of fascist psychology. And I believe that by that we have done the world a great disservice."

The politicians and the papers tried to hide their disappointment and surprise. The words of the young Revolutionary Guard were reiterated: "The imam said Carter would be defeated, and as always the imam has been proven right."

But the apprehension was clear. Now, more than a year after the capture of the hostages and the American Embassy -- the "nest of spies" -- the stirred up hatred against the United States has dissipated, lost its appeal to the masses.

Rather, the costs of the affair have slowly become clear to the Iranian populace: the isolation, the lack of military hardware, the loss of foreign credit. The fundamentalists have found that, with the United States no longer a bogeyman or a means of consolidating their power, their action against America and the hostages is boomeranging on them.