AN INTELLECTUAL visitor from another planet, arriving on earth for the first time and intending to settle, might base his choice of country on the views of leading writers. Arriving this week, he would discover that Mr Graham Greene likes the Soviet Union. And he would quickly guess how cruelly oppressive is the Western world when he discovered that Mr `It's not so bad; I had a flat in Knightsbridge.' Greene lives not in Russia but in- France, presumably against his will. Then he would apply for right of abode in the. Soviet Union and be surprised to learn that he was one of few and that those wanting to go the other way were many. Then, .being an intelligent creature, he would realise that on earth, when great novelists, speak about politics, they only mean to amuse, and he would laugh good-naturedly. He would be shocked that some sour-faced people who had been to a place called Gulag which Mr Greene likes very much could not bring themselves to share the joke.