The two young men are alike in so many ways - both students in their mid-20s who came to college here from their homes in Iran, both Muslims from middle-class families that are supporting them here, and both with intense feelings of patriotism for their troubled native land.

There the similarities end, and the pair seem as sharply divided as it is possible to be on the great issues of freedom, imperialism and ideology that have dominated the 20th century. As the shah and his shahbanou were touring official Washington yesterday, one of these young men wore a hood and denounced his country's leader as a "fascist butcher" while other waved a tiny Iranian flag in enthusiastic support.

Listen first to Ali Mohemade, pro-shah. Mohemade, 27, sports a heavy black moustache and has an open, friendly manner. As he bantered with his friends on a downtown street corner yesterday while waiting for the shah to appear, he had a casual, almost collegiate air. He clearly was enjoying himself.

"I cannot say exactly why I like the shah," he said, struggling for the right expressions. "It's a feeling: I love him. In your case, someone could say, 'Jusus is a son of a gun,' but you still love him. I love the shah since he is the king, and he is a nice person."

Mohemade said he does not believe all the accusations that the shah is a dictator, that the shah is controlling the country through a repressive secret police organization, the SAVAK is like the FBI," Mohemade explained. "It protects our people against those who want to do something against our country, against the shah, against everybody."

There is a believable, even compelling normality about Mohemade. He is studying to become an English language teacher because "you can get good pay." He is not out to change the world. In fact, he is having fun. "I am a Muslim, but I drink . . . a little bit," he said with a laugh that his friends joined in.

Ali Mohemade came to the U.S. six months ago and entered an English language program at a junior college in Dallas, Tex: he couldn't remember the exact name of the college. Back home in Tehran, he said, his mother is a seamstress and his 12-year-old sister goes to school. His father, who was a government agriculture official, died several years ago.

Actually, that proved to be somewhat of a bonanza for Ali Mohemade. The death brought a government Pension that enabled the son to travel throughout Iran for several years."I had a good time," he explained. "I took a trip, lived in one city or another. I was like a tourist. I worked a few days a month, maybe. If you have money, why should you bother yourself with work?"

Mohemade said that his family is supporting his study here and that he receives no subsidy from the government. Reza Abrhamy, a friend who was listening to the interview, said that he, too, was supported by his family - but that on three occasions when he was low on cash he asked the Iranian government for help and received a total of $1,800 this way. "I wanted it to buy a car," he said.

Mohemade said he paid his own way to Washington, using money he had saved for the Christmas holidays. He does not plan to stay long. "It's cold here," he said. "I think I'll try it in the summer-time."

About a quarter of a mile away, on the Ellipse just south of the White House, the young Iranian in the white hood broke away from a chanting circle of his friends and sat for half an hour with a reporter on a stone wall that surrounds the national Christmas tree.

He sat in the warm November sun, nameless for fear of government reprisal, his voice level, his right hand chopping home his points - the very picture of that special fearful seriousness that goes with being revolutionary, and which Americans came to know so well in their own young protesters nearly a decade ago.

"In my family when I was growing up, the aura of SAVAK always stopped any political discussion," said the student. "My father would say, 'Stop! Saying that will get you into trouble. I don't want to be tortured, to be driven out of business.'"

This student, who is studying engineering at a university in Washington, said he plans to go home to work - yet he fears that, in doing so, he will be exposed to possible capture, at the very least to harassment. "You know, you just feel it in your guts when you are totally repressed," he said "when there is no freedom of speech, no freedom of assembly, no security in choosing your own destiny."

Torture, he said, has been part of his life, something he worries about. "It's really unbelievable," he said. "But after a friend spent six months held by SAVAK, his brother said all his body was burned with cigarettes and this is quite a mild torture. I have heard they put underground people on toasting frames (over hot coals)."