No political leader anywhere can match the success Anwar Sadat has enjoyed as an international statesman. So the sour view of the Mideast he laid out for me in an interview the other day bears reporting in detail -- the more so as it provides the context for the separate meetings with President Carter that Sadat and Prime Minister Menachem Begin will hold beginning next week.

Saudi Arabia is the subject of Sadat's most startling comments. He acknowledges that he stopped relying on the Saudis when they refused to support the move he made at the Camp David summit for peace with Israel. Even so, he was shocked by the uprising in Mecca earlier this year. He said:

"Believe me, if I had been asked before it happened, I would have said that what took place in Mecca could not have occurred in 20 or 50 years. Well it happened now, and that proves that this is a very small world -- the world of the transistor."

As to measures that would avert future troubles in the kingdom, Sadat said, "I don't see any real steps." He added that if the Saudis wanted to change their regime, "nobody could oppose it." Of the present Saudi rulers, he said: "The future for them is not too bright."

Syria, Sadat said, is in a state of "civil war." He thought that eventually there might be a "massacre" of the Alawite minority grouped around President Hafez Assad. He said he did not think Assad would be in power "before this year is over."

King Hussein of Jordan and Yasser Arafat of the Palestine Liberation Organization were mocked by Sadat for their inability to stick to a strong position respecting a settlement with Israel. He charged that Arafat gave the impression of willingness to coexist with Israel when he talked to Bruno Kreisky of Austria, but said "something completely different in Beirut." Of King Hussein, Sadat said: "Every day he adopts a new idea."

I suggested to Sadat that at least President Saddam Hussein of Iraq headed a strong regime. Sadat acknowledged that the Iraqis "frighten the sheikdoms of the Persian Gulf." But he said that "every day brought a new incident against Saddam Hussein." In fact, he said, "Iraq is shaky."

Iran, he said, would probably "be in chaos the next 10 years." During the next year he saw a "sharp turn to the left." He insisted that the Ayatollah Khomeini was a front for uncompromising radicals. "They say Khomeini rules," he observed, "but who knows?"

Libya, his neighbor to the west, has become a "storehouse of Soviet arms." He said that if the Libyan leader, Col. Muammar Quaddafi, became too obstreperous, Egypt might have "to punish him." But he denied published reports that Cairo had in fact developed a plan -- vetoed, some said, by the United States -- to unseat Qaddafi. He said change in Libya was "for the Libyan people to decide. You cannot throw down any regime from the outside." l

The Soviet Union, according to Sadat, was the chief beneficiary of all the troubles. He claimed he had been warning about the Soviets for years -- "in Angola and Zaire in 1977; Ethiopia and Somalia in 1978; in Yemen in 1979. Now in Afghanistan."

The United States, Sadat believes, bears much of the responsibility for the shift in power. "You were wrong in your assessment before the shah was forced to leave Iran," he said. "You failed in your responsiblity as the leading superpower to protect the sheikdoms of the Persian Gulf," which are crucial to the supply of oil. "Now," he said, "the Persian Gulf is the hottest area in the world."

"You are just beginning to mend," Sadat said, when I asked him about American performance since the invasion of Afghanistan. Somewhere in the future he sees a showdown between Washington and Moscow in this area. "You will have to maintain a presence and check them," he said.

Holes can easily be poked in Sadat's assessment. It reflects disappointment that none of his neighbors have joined his quest for peace with Israel. It is flatly wrong in some details. But the general picture seems right to me. And though following through on the Egyptian-Israeli peace initiative cannot possibly correct all the ills, it is the best thing going. As Sadat puts it: p"There is no other alternative."