When Big Jimmy Lakas was still a student up at Texas Tech years ago his friends used to tease him.

"My good old buddies," he says with a grin, shaking his mammoth head and chuckling. "They always used to call me a wetback and a greaser. My buddies were the greatest people in the world. They'd say, 'Jimmy, when you go back to Panama and start zee revoluzeeon, we all be zee daid.'"

He thunders his laughter across the room of the presidential palace, then pounds his enormous ham-like hands on the table. "And by golly I did. And we whopped 'em."

He never before belonged to any party or politics, he says now with a still incredulous expression. "I was so naive. I didn't know anything about politics. My friends used to say, 'Boy, stop sayin' that! You're the president.'"

It is a bit odd that a big Greek architectural engineer and businesman with a Texas accent and a Chill Wills voice would end up being the president of Panama under a military dictator. Odd any place except Panama, that is.

He suddenly turns solemn.

"Something happen in my life on Sept. 29, 1968. My daddy died." There is a long silence as Lakas stares out to the sea through the huge picture window in his office. "The fellow who was supposed to take over the nation that Oct. 1 had bought all the flowers in town to celebrate. Well, we're Christians. And I had to go out to look for a white cross made out of lilies. And none of the florists would sell me any flowers . . . on orders from Arnulfo Arias.

"It helped me make a decision in my mind then. To join with Omar Torrijos and overthrow him."

Jimmy Lakas is a showman. He knows what plays and what doesn't. When you ask him to tell a little about his background he scratches his head, grins and says, "Let's see, how can we make this colorful?

"My grandfather brought his daughter over to Panama from Lesbos to marry my father who was from Pelopenesus. I was born in Cristobal on the Atlantic side of Panama."

He didn't stay there very long, ended up in school in Panama City, then went to the Canal Zone Junior College, then to Texas to study architectural engineering. Building an Image

"I always wanted to be a millionaire," he says. "I used to stand in front of the mirror for hours and say, 'Why, you millionaire, you.' I started out doing the only building in Colon, then I moved to Panama City and commuted for several years." He worked for a while, for the Department of the Treasury, and then married his wife Elizabeth. "Nineteen years of slavery," he says. "But I thank the good Lord I was so fortunate to find such an understanding wife."

"And," he says, rolling his eyes toward heaven, "I hope the good Lord helps me go out the wide open door without anything to be ashamed of."

Realizing that much more of this is not going to go over, Lakas quickly changes the subject and drops his pious demeanor.

At 52, Jimmy Lakas is "Big Daddy." He has the jovial Southern patriarchal humor and warmth, the sly businessman's wiles, the masculine attitudes of chivalry and the clear belief that women are ornaments, sexual objects to be admired and protected, the sudden anger at being crossed or disobeyed. You can almost see him pounding his gigantic fist on the table and bellowing at Elizabeth Taylor "Dammit Woman . . ." Behind the Bravado

But for all his bravado, Jim Lakas is despondent. He tries to carry on, tries to put on a brave face but that old Greek-Texan-Latin American spirit just isn't there, the way is must have once been.

Once he was Omar Torrijos' close confidant and friend and one of the most powerful men in the Panamanian government.

For all practical purposes he is still the president and still running the country. But he's not getting the glory. Torrijos is getting the glory.

There can only be one star in Panama and Torrijos has decided to fill that role while everybody else does the work. Besides, according to local potltical reporters, lately Torrijos has become resentful and suspicious of the Panamanian business community because Panama is so dependent on it. Lakas has become the business community's liaison.He even meets with a group of American businessmen once a month. "We're the only Latin country in the world with a gringe kitchen cabinet," he jests. But Torrijos, annoyed according to the Panamanian observers, has begun to freeze Lakas out.

Lakas' hulk sinks into the chair in his elegant office-apartment in the palace and he begins to reminisce.

"I used to think of my old buddies up in Texas, about how they teased me about the 'revoluzeeeon.' And I think that this coming October I've got to walk away from this job after 10 years of serving my country . . . walk away with nothing. I wish I were in the United States," he says with a touch of bitterness 'At least there if you're the president you walk away with cars and secretaries and a salary. See in 1972 we decided to go with this new type of presidency. I was elected president under the new constitution, for which I cannot be reelected."

Jim Lakas is pretty frank, too, about disliking his job. "No, I don't like it. Like I said, you're prepared for these things. Like I wanted to be the best engineer in Panama. But destiny placed me here. A Friend Named Torrijos

Jim Lakas first met Torrijos after he moved from Colon to Panama City and Torrijos had taken some material from the government "which he didn't use properly. He was a captain then. A cocky little captain. I'd say he thought I was a very defiant man. I just looked him in the eye and I said, 'you go put this back in place.' I think he liked the way I complied with my duties regardless of my feeling for him."

They remained friends and shortly after Torrijos had overthrown Arias, he and Lakas went on a trip to Mexico. While they were there, there was an attempted coup against Torrijos.So the story goes, it was Lakas who encouraged the dejected Torrijos to return to Panama and recapture his dictatorship. And it was for that reason that Lakas ended up being president.

"Let's put it this way," says Lakas. "The good Lord has seen to it that we've always gotten together when things have gotten tough in our life. We can trust each other. Give each other moral support, friendship and loyalty. We can walk hand in hand, whenever friends talk to each other and hearts feel for each other . . ." He looks up to see how this is going over . . . smiles a bit sheepishly . . ." or something like that.

"If he's done something wrong I'll walk right in and tell him," says Lakas, "I'm a volatile person.He's not. I'm nervous. Most of my boys like to deal with Omar better than me I'm much stricker. I'll just holler at 'em. But I would say I'm good at running the country. I'm more disciplined. He's more like an artist. He's inspired . . . I'm on the job. I get the job done."

"I wouldn't call Torrijos a dictator," says Lakas. "A lot of us make decisions around here and then tell him about them later. When there are big devcisions they have to be decided by the counsel with me presiding. We talk, we vote, then we go with the majority. This is one of the things everybody loves about Torrijos. He has full power not to be stopped by anybody. But he's never used those powers without consulting somebody."

Lakas thinks the image that Torrijos got for being leftist is unfair. "I think it was because he was trying to get Uncle Sam's attention, to say 'We're here and we want a new treaty.

So Panama had to look for friends in common. Some were small or underdeveloped. But with all our needs we never aligned with China and Russia. We needed something to jump us from No. 15 on the Panama desk at the State Department to No. 1.

"But the image didn't do Torrijos any good. It painted him as a Communist. And they tried to dirty his name with other things. It hurts me and him. I know he loves kids too much to do this terrible thing with drugs to them."

Lakas hesitates and decides not to go into the drug thing any more.

"Omar has met Castro, Begin, Qaddafi, Carter. His cause is to get Panama in the news. That was his job. But now that he talks to the president of the United States and says how wonderful the people in the U.S. are - now that makes him a rightist. They don't give little countries very much opportunity to choose their friends. Now they've all joined together and call themselves the Third World. They want to push over to the left anybody who has social feeling for their neighbors . . . Well I think it's a doggone line. I'd consider myself to the right. But you don't have to choose the left or the right to help people and love people." Good Old Boys.

Some people are dumb enough to let Lakas' Texas good-old-boy routine fool them into believing he's not too smart. But Jimmy Lakas is just about as dumb as Bob Strauss, which is to say he's plenty shrewd. To be sure, there's that teasing. "I'm-gonna-put-one-over-on-you-and-you're-gonna-love-it" number. But Lakas knows how to play hardball when he has to and that becomes clear when the subject of human rights is brought up.

"Look," he says, pulling himself up and leaning his massive body across the table," we had a revolution here. And some people don't respect martial law.

"The disrespect of some people here in Panama. They defy the orders given. If we hadn't been strict there would have been big bloodshed and we'd all have been very sorry. In the olden days, from what I've heard in Texas, the cattle rustlers and hog thieves in Texas - their lives lasted to the nearest tree if some posse was after them. In other words, there's a time and place for everything. In the process of a revolution there are always some unfortunate things that occur."

As for those who were exiled, he says, "If you put them in jail you just make martyrs and heroes out of them. We thought the best thing for nationalism and peace and the banking community was to send them away.

"We're not very proud of it, but we had to do it. Because once you start the bloodshed, well, you know where it starts, but you don't know where it's finished." And Now the Treaties.

Jimmy Lakas is Greek, but he is probably more pro-Panamanian than many of his fellow countrymen. So it is hard for him to be charitable toward the Zonians and their position against the treaties, even though he went to the Canal Zone Junior College before he went away to Texas.

"Nobody's giving nothing away," he growls. "This here strategic and geographic location is all we've got in this here little country. We want some of this. Our little country, it looks like little old San Antone. Have you found anybody treat you wrong?"

His eyes twinkle now. He's having fun, launching back into his cowboy act. "We're a little old meltin' pot. Here I am first generation fighting for my country and there are third-generation Zonians saying, 'Who are you, a Greek, telling us what to do?'

"But you know, some of them don't even fit in the states. I knew one who went Texas. He didn't fit. It was too rugged and uncultured. For me it fit like a glove. In Texas they tell you whether they like you or not. I like that."

The Zonians, he says, "are scared of everything. They're strictly communism. Everthing is given to them. They're afraid of the unknown. But God Bless America, honey. Who knows whats going to happen in the next 23 years?"

As for his own future, "Maybe I'll get a pension," he says gloomily. "Maybe some of those old buddies of mine, those senators up there, will please write in a pension in the treaties for the president of Panama.

"It isn't fair. A man spends six years of his life, the most productive years, then goes back to pouring concrete." His huge head drops; he stares at the floor of the presidential palace. It's just not fair."