Sphere of influence: An area in which one nation wields dominant power over another or others. -- Random House Dictionary

THE TERM, IN REALITY, means no more than the common habit of recognizing who is the biggest, and usually the toughest, kid on the block and keeping out of his way.

Among nations, its most important meaning at the moment is general acceptance of the fact that the Soviet Union's writ, by the power of its arms, runs to all her neighbors in Central Europe, most especially Poland.

And it means that the United States, however it may verbally protest that Soviet sphere of influence, is not going to try to alter that fact, at least not by force. That, of course, is why Reagan administration officials rule out any American military action should the Kremlin use force to crush the Solidarity union movement in Poland.

But the biggest kid on the block often is a bully and becomes so intolerable that somebody does something about him. In time, this applies to nations, too.

Those who populate the foreign policy think tanks are full of talk about the eventual end of the Soviet empire but they are very fuzzy as to the when and how. To see that possibility you have to take a long view; the writ of the Roman empire ran to Judea but its eventual end was of no comfort to the defenders of Masada.

The acceptance of spheres of influence as a fact of international life, especially in this nuclear age, is considered by many to be practical politics. Historically, in the United States that acceptance has had a rather wicked, if not downright immoral, connotation.

When Gen. Eisenhower first ran for president in 1952 there was much Republican criticism of the wicked Democratic deal between Roosevelt and Stalin at Yalta that had, so it was contended, handed over Eastern Europe, most especially Poland, to the communists.

John Foster Dulles proclaimed "a moral or natural law" to determine right or wrong and from this grew the idea of a "rollback" of communism and the "liberation" of the satellite nations. But when he became secretary of state, Dulles had only words to offer when the post-Stalin eruptions came in East Germany, Poland and Hungary. In reality, Eisenhower and Dulles had accepted spheres of influence.

These two ways of looking at international relations -- they can be called the moral and the practical -- seem to be as old as man himself. Jimmy Carter's human rights view of other nations is a recent manifestation of the moral although Carter never challenged the Soviet sphere in Eastern Europe. Woodrow Wilson's aim of making the world "safe for democracy" was of a similar vein.

During World War II, Franklin Roosevelt was most reluctant to state America's post-war aims much beyond the creation of a new world organization to keep the peace. But Winston Churchill and Joseph Stalin were less idealistic.

On Oct. 9, 1944, Churchill met Stalin in the Kremlin. The prime minister jotted down on a half sheet of paper a list of nations and percentages of influence for the Russians and the West in the post-war world. He wrote: o Rumania: Russia, 90% The others, 10% Greece: Great Britain, 90% (in accord with U.S.A.) Russia, 10% Yugoslavia: 50-50% Hungary: 50-50% Bulgaria: Russia, 75% The others, 25%

Stalin accepted Churchill's figures. When Churchill suggested that perhaps the paper might best be burned, Stalin said "No, you keep it." He did. Churchill told Stalin, the minutes of the meeting show, that "it was better to express these things in diplomatic terms and not to use the phrase 'dividing into spheres' because the Americans might be shocked." When Averell Harriman, then the American envoy in Moscow, heard what Churchill had done he told him that FDR would "repudiate" such a cynical division.

There was no figure for dividing influence in Poland. That nation's fate was to be settled at the Yalta conference of the Big Three shortly before FDR's death in early 1945. The French have always criticized Yalta because De Gaulle was not invited, but the American criticism has come from those who felt that FDR and Churchill had "immorally" turned over Eastern Europe to Stalin by accepting his sphere of influence.

Charles E. (Chip) Bohlen, FDR's interpreter at Yalta and later ambassador to Moscow, denied throughout his later life that the United States ever had accepted a Soviet sphere of influence.

In his memoirs he told of rejecting a proposal from George Kennan, a fellow Sovietologist, that the West compromise with Russia and "divide Europe frankly into spheres of influence -- keep ourselves out of the Russian sphere and keep the Russians out of ours." Bohlen saw at Yalta that Stalin's aim was to protect the Soviet Union and to do so "meant the establishment of satellite governments through Eastern Europe."

At the conference, FDR argued for settling the Polish issue by free elections. But "when Roosevelt said he wanted the Polish election to be pure, like Caesar's wife, Stalin commented, 'They said that about her but in fact she had her sins.'" In fact, too, Stalin had the Red Army, then all over Poland. Elections did not count.

Bohlen concluded that FDR "has been criticized for not doing more for Poland at Yalta. I cannot agree. The concessions that he and Churchill made in their eagerness to avoid a split were perhaps a mistake, but the agreement, although not what the West had wanted, appeared to us, with some doubts, to be acceptable. Had it been fully observed, Poland conceivably would be an independent country today."

When Roosevelt returned from Yalta, he spoke to a joint session of Congress, sitting in a chair in the well of the House. In the course of a long, rambling speech that betrayed his illness, Roosevelt said the Crimean conference "ought to spell the end of the system of unilateral action, the exclusive alliances, the spheres of influence, the balances of power, and all the other expedients that have been tried for centuries -- and have always failed."

But that was not to be. The next year Churchill proclaimed in his "Iron Curtain" speech: "Warsaw, Berlin, Prague, Vienna, Budapest, Belgrade, Bucharest and Sofia, all these famous cities and the populations around them lie in what I might call the Soviet sphere. . ." Only Vienna would fully escape, and then only at the price of Austrian neutrality between East and West.

It is a rare American practitioner of foreign affairs who has openly accepted the idea of spheres of influence; even Henry Kissinger, to many the epitome of realpolitik, avoided the term though he practiced its reality. Recently, Jeane Kirkpatrick, the Reagan envoy to the United Nations, said in reply to a reporter's question about Poland and the Soviet "sphere": "I think that the United States hopes for the national independence of all people and I don't really think we accept the idea that one nation has the right to dominate other peoples in any part of the world."

This reflection of the old Wilsonian democratic ideal, even though linked to the acceptance of the military reality, continues to be basic to the American character and policy. How much it has annoyed so many others is perhaps best illustrated by the comment to Churchill prior to Yalta by his envoy in Washington, Lord Halifax:

"The trouble with these people is that they are so much the victims of labels: 'Power Politics, Spheres of Influence, Balance of Power, etc. As if there was ever such a sphere of influence agreement as the Monroe Doctrine! And, as I can only tell them when they talk about being outsmarted . . . they evidently outsmarted somebody when they made the Louisiana Purchase!"