Defense Minister Mustafa Tlas is a unique character in a government where most of the significant figures shun the press, and those who do talk dutifully defer to the careful, calculated language of President Hafez Assad.

In domestic politics, Tlas plays a role here like the fools of Shakespeare, who speak the words others are afraid to say and still survive where others would not. But few make the mistake of taking Tlas for a fool.

On foreign policy, no one makes the emotional underpinnings of his country's stand in the Middle East more comprehensible or states them more bluntly than the general.

"Why do you want the Arabs to be slaves of the Israelis?" Tlas demanded of an American reporter. "You want 150 million Arabs to bend before 3 million Israelis?"

In an attempt to justify suicide bombing attacks on Israeli troops, Tlas found a link with U.S. policies. The stand of the United States is so completely biased toward Israel, said Tlas, that some young Arabs see no way to confront the problem but to blow themselves up -- along with their enemies.

"A young man who reads the American position has no alternative but to commit bomb attacks and suicides," he maintained.

Tlas clearly has Assad's trust. Recalling that the two men began their military careers at the same time, a western diplomat said, "Tlas was a young officer with the president, and he was chief of staff in 1970, when Hafez took over, and he backed him." In a country where governments have changed mainly by coup d'etat, it is important, he added, that "Tlas is no rival."

Last year, while President Assad's flamboyant and troublesome brother Rifaat was out of the country, Tlas told the West German magazine Der Spiegel that Rifaat "is for us persona non grata forever" and suggested that if Rifaat or anyone attempted to defy the president he would likely wind up "shorter by a head."

Rifaat Assad is back now, no shorter, but a great deal less powerful. The Defense Companies he once led as a personal army have been put under the command of another old military school classmate of President Assad and Tlas.

The gossip of the capital is that Rifaat, having returned from his sojourn in Geneva at the end of last year, now wants to leave again but is not allowed to. There is no confirmation of these rumors, but the fact that they are circulating says something about the internal balance of power at the moment.

Tlas, meanwhile, stays right where he is, undaunted and comfortable with his own responsibilities.

The general receives visitors in his home. Peasant petitioners wait in the street outside the relatively modest house, knowing that he may stop and jot down their requests as he drives out. Influential businessmen and officials drop by. There is always an offer of tea. The prelude to conversation is marked by embraces, courtliness, gentility and hospitality. Tlas smiles easily and confidently, his tone never quite as sharp as his words.

"I am beginning," he declared, "to agree with the French president Charles de Gaulle. He said the United States has no foreign policy, only foreign problems.

"Look at the United States in Lebanon. A total failure," he said, grinning peaceably.

"How can we have respect for the United States when we see the biggest of countries coming and supporting the invasion of a tiny country like Lebanon? The cluster bombs dropped on Beirut by the Israelis in 1982 were only two months old, straight from California. They were the latest armaments and weaponry from the United States.

"And still President Reagan wonders why we don't love the United States in this region.

"The Americans won't sit down with the Palestine Liberation Organization even though we think [Yasser] rafat is one of theirs."

The United States and Syria continue to talk. Assistant Secretary of State Richard W. Murphy recently spent five hours with President Assad, but Tlas speaks of "fact-finding" visits with good-natured irony.

"Withdrawal from the occupied territories, a solution to the Palestinian problem through an international conference and the Fez Arab League conditions are the maximum conditions we can agree on with Israel," said Tlas. "And every time we have a U.S. envoy here we repeat these conditions, and every time he returns to Washington he seems to forget them. So they send Murphy again."

Syria's support of Iran in the war against Iraq is often described as a problem for Syria in its relations with the rest of the Arab world.

"We insist on our friendship with Iran," he said. "We have no interest in creating enemies of 40 million Persians. One enemy" -- that is, Israel -- "is enough."

Syria felt that if Iraq had won quickly against Iran, it then would have moved against Syria. "Any enemy of my enemy is my friend," Tlas said.

Iran's government is fundamentally, militantly religious, Syria's is profoundly secular. That is no problem, said Tlas, although here he did shift away from the subject with some apparent discomfort.

"We are mostly Moslems, but we are also friendly with a godless country like the Soviet Union because they support us. There are daily radio spots on Radio Moscow explaining what Zionism is. They are very much in favor of our attitude."