Washington — Much like Poland itself, the Polish ambassador who defected to the West is a man of startling contrasts. Through a long and distinguished career, Romuald Spasowski was both an aristocrat and a communist, both a cultured intellectual and a tough negotiator.
The ambassador's multifaceted personality combined two of the best traits which Poland has had to offer the world: patriotism tempered by independent thought.
Mr. Spasowski also happened to have been, for more than a decade, his country's top diplomat.
But those who knew Spasowski well in this capital say that his disillusionment with the Polish brand of communism went back many years. They were not surprised when the tall and courtly Polish ambassador stepped before the microphones at the State Department on Dec. 20 and declared he was seeking political asylum in the United States. He was defecting, the ambassador said, as an ''expression of solidarity'' with Lech Walesa, leader of the polish trade union movement. In an eloquent statement, he protested against the repression in Poland, which he described as a ''state of war against the Polish people.''
The Polish authorities were quick to denounce Spasowski for his defection, and branded him a ''traitor.'' They announced that criminal proceedings would begin against him.
But in Washington, praise for the ambassador came from all sides. President Reagan held an emotional meeting Dec. 22 with Spasowski and his wife Wanda.
''I'm very proud that he is here in this office,'' the President said. ''I think we are in the presence of a very courageous man and woman who acted on the highest principle, and I think the people of Poland are probably very proud.''
''I dealt with Spasowski when I was in the White House, and I knew then that he was a true patriot,'' said former national security adviser Zbigniew Brzezinski, who is of Polish origin.
''In my dealings with Ambassador Spasowski as a colleague, I always found him a stalwart Polish patriot and a person of remarkable integrity and judgment,'' said the British ambassador in Washington, Sir Nicholas Henderson.
''He was a tough negotiator and a very good dialectician,'' said Richard T. Davies, a former US ambassador to Warsaw who dealt with Spasowski when the Polish ambassador was the No. 2 man in the Polish Foreign Ministry. ''He always had a good reason for the positions he took. . . .''
Ambassador Davies said he tought Spasowski's disillusionment was a matter of ''gradual erosion'' going back a number of years. By the time he came to Washington for his second tour as ambassador to the United States, Spasowski's discouragement was beginning to show. He told one Carter administration official that he was a ''former Marxist.''
But Spasowski had begun his career in communism with many of the right credentials.
His father, Waladyslaw, a professor of pedagogy whose origins went back to the landed aristocracy, became in the 1920s and '30s a distinguished left-wing intellectual. He never went so far as to join the Communist Party, but he greatly admired the Soviet Union. His father committed suicide in 1941 after being tortured by Gestapo interrogators. According to Davies, Spasowski's decision to join the Communist Party probably stemmed in part from his father's suicide. For Spasowski, the only hope for Poland in the face of Nazi brutality seemed to lie in alliance with the Soviet Union. Spasowski fled to the Soviet Union after his father's death and fought his way back into Poland as an officer with a Polish army unit which was formed in the Soviet Union.
Following the liberation of Poland by the Soviet Union, Spasowski shared in the hopes of a generation of young Poles. But under both the Gomulka and Gierek regimes, Stalinism crushed those hopes.
''As time went by, he saw more and more the way in which the Communist Party was being corrupted by power,'' said Ambassador Davies.
Davies feels that the Solidarity trade union movement in Poland was thus ''enormously inspiring'' to both Spasowski and his wife Wanda, who is a devout Roman Catholic.
Another acquaintance of the Polish ambassador and his wife said that in recent months Mrs. Spasowski began to carry Solidarity buttons in her purse.