Lenin, who gifts included a capacity for phrase-making, albeit of the cynical sort, once pronounced his formula for big power diplomacy. Promises of the state, he said, like pie crusts, are meant to be broken.

With the papers filled by accounts of wars of liberation, guerrilla attacks, airlifting of troops and attempts to put out brushfires throughout Africa, that old maxim realt-politick mentality would seems to be as applicable as ever. But it isn't so much the Russian role in Africa that arouses both new concern and a sense of deja vu these days. It's the Cuban connection that commands attention.

Just a year ago, in the first spring of the Carter administration, an end to the rancorous and often violent Cuban-American past appeared in sight. Good will was the order of the day. The barriers were coming down: touring groups of American journalists, politicians and basketball teams were being welcomed warmly in Cuba. Castro was accommodating. He was telling people like Bill Moyers that he believed Jimmy Carter to be a man with a "sence of morals" who might bring an end to 16 years of hostility between his country and the United States.

Expressions of cordiality were not limited to the Cuban side, either. The president had been in office less than a month when he held out the promise for dramatically new relations.

Carter hoped, he said, the Castro's stated desires for improved relations "can be followed up by mutual efforts to alleviate tensions and reduce animosities." He didn't limit his remarks to vague hopes( the president was quite specific in addressing how to restore normal relations! He said.:

"If I can be convinced that Cuba wants to remove their aggravating influence from other countries in this hemisphere, will not participate in violence in nations across the oceans, will recommend the former relationship that existed in Cuba toward human rights, the I would be willing to move toward normalizing relationships with Cuba as well."

There was another aspect to Carter's proffering of a new beginning between the two nations. It had to do with Cuban forces in Africa, specifically Angola. The president said he wanted very much to see the Cubans remove their soldiers there and let the Angolans make their own decisions about their government.

"We've received information from indirect sources," Carter said, "that Castro and Cuba have promised to remove those troops."

That promise, he went on, was a key not only toward resolving the Angola situation, but ultimately toward rapprochament with America as well.

In the immediate months that followed, the news about Cuba continued to be favorable. Our reconnaissance flights over Cuba, which had figured so notably in the missile crisis of 1962, were said to have been called off by the president. American food and medical shipments to Cuba were authorized for the first time in nearly two decades. Talks were progressing about resolving fishing and maritime boundary questions.

All the while, private negotiations were taking place between the two countries amid more and more hopeful signs. A scholar, Abraham F. Lowenthal, returned from trips to Cuba with positive news:

"Cuba is eager to resume commerical and political relations with the United States,? he reported, in a lengthy article in The Washington Post. "Provided the Carter administration shares that aim, Cuba seems willing to reassure the new U.S. government on several issues of obvious concern to Washington: Cuba's policy in Africa, Cuba's relation to Puerto Rico's independence movement and the principle of compensation for U.S. properties expropriated by cuba."

Then early last June, the two nations agreed to exchange diplomats for the first time in many years. Cubans returned to their old elegant embassy on upper 16th Street in Washington, now operated by the Czech government, and official American representatives returned to Havana.

As only one indication of the tone of those times, less than a year ago, Castro held a lavish state reception for a group of visiting American businessmen and their families. The Americans were wined and dined. Amid the flow, the wife of an American big business executive was introduced to Castro. She'd like to touch his beard, she said as they were introduced. Then, with Fidel's blessings, and the uproarious approval of Cubans and Americans alike, she ran her fingers through Castro's famous - and fulsome - beard.

New era, indeed.

How fast those hopes were dashed became clear in a Castro speech at the end of the year. Cuba would continue its assistance to Angola, he said - and to Mozambique and Ethiopia, as well as to guerrilla movements in Rhodesia, Namibia and South Africa.

As for Puerto Rica, he was unyielding in expressing support for independence from the United States there "as long as there is one Puerto Rican that defends the idead of independence." Compensating the United States for properties seized by Cuba was out of the question. And, emphatically, he left no doubts where Cuba's main interests lay.

"Our relations with the Soviet Union and the Socialist camp are decisive," he said, "and the United States will never be able to substitute those relations."

We had been thrown back into the rigid and bitter positions of the past. Castro began denouncing the U.S. policy as "blackmail" in the flamboyant manner of old, and his troops kept moving into Africa.

To anyone who has watched this process over the years the present Soviet-Cuban ventures are a dismaying reminder of the continuing harsh realities of international idological struggles. But, from the American perspective, there are notable differences from the past.

This time, it's the Cubans who are fighting and dying on a number of fronts. Their African adventure comes after a long and total failure at fomenting revolution throughout Latin America. And, unless we recklessly become more directly involved in the new conflagration, this time it's the Cubans, who are going to pay the terrible price of waging a land war in a far-off and unfamiliar clime.