Rome — ''We would have the Russians on our doorstep the next day,'' says Laura, an impassioned and articulate grandmother, when asked her views as to what would happen if the Italian Communist Party were ever granted an active role in government here.
She is voicing, in simplified terms, the fear that has kept the Communists out of a long series of multiparty coalition governments. The Communists have been excluded even when they have received more votes than any other party except the leading Christian Democrats.
There are hammer-and-sickle emblems in the lobby of the headquarters of the Italian Communist Party (PCI) here in Rome.
There is a wide double door that opens electronically (a rarity in Italy); a higher degree of order and efficiency than is found in most other seats of Italian politics; and a huge antinuclear poster on the wall. And employees actually refer to each other as ''comrade.''
As Italians lose confidence in the revolving-door style of politics that has prevailed here since 1948, Italy's Communist Party seems to be waiting in the wings, watching for its opportunity to provide an alternative.
Lately there have been signs that the PCI may be edging Westward.
Two cartoons recently appeared in the national Communist Party newspaper, L'Unita. In one a small boat sailed past the Statue of Liberty in New York Harbor. Aboard were PCI members, including party leader Alessandro Natta. The caption read, ''The discovery of America on the part of young Communists.''
The other cartoon showed Marx and Lenin, with the PCI's annual rally going full tilt in the background. Lenin turns to Marx and asks, ''Why bother going? We don't know anybody there anyway.''
Are Italy's Communists really moving toward the United States ideologically? Are they easing away from the Soviet Union?
A well-informed Western diplomatic observer here says ''no'' to the first question, ''yes'' to the second.
''It would be incorrect to say that the PCI is pro-US,'' he explains.
''What happened at the Festa dell'Unita (the annual PCI rally) this year simply shows that the Italian Communist Party is paying more attention to the entire world.''
Indeed, according to a non-Communist who attended, this year's rally had more of a ''county fair'' atmosphere than an earnest, ideological one.
Rock music blared. Carnival rides, pop singers, a futuristic exhibit, and a display of IBM computers were popular attractions. There were even performances by the New York City Ballet.
''No one,'' this observer remarked, ''bothered to visit the Communist propaganda booths.''
A press spokesman for the PCI, Francesco Demitry - who describes himself as a devout Roman Catholic - explained, ''We are not turning toward the West. But we are turning away from ideologies. Marxism and Leninism are valid lessons, but we are interested in other things.
''We have freed ourselves from these doctrines.''
Indeed, the ideological separation of Italy's Communist Party from the Soviet Union is largely taken for granted here.
This is exemplified by the title of a book considered to be a definitive text on recent trends in the PCI. Written in 1982 by leading journalist Giampaolo Pansa, a Socialist, the book is entitled, ''October, Farewell'' - a reference to the USSR's October Revolution.
The book characterizes the communism of the PCI as ''a national, utopistic communism . . . or rather, a more pragmatic form of social democracy in the European mode.''
On a number of occasions, Communist leaders have stated support for Italy's membership in NATO. But Giuseppe San Giorgi, a spokesman for the Christian Democratic Party (DC), which has been at the helm of Italian politics for 40 years, is uncertain as to what this means.
''Their position is ambiguous,'' he says. ''(Former PCI leader Enrico) Berlinguer gave interviews in which he said that he felt more protected being aligned with the West. He said that he supported Italy's membership in NATO.
''But when the interviews appeared in the official Communist newspaper L'Unita, these comments relating to NATO had been removed - censored. In Parliament, on certain matters of foreign policy, the PCI votes against NATO. They are neutral and pacifist.''
''The Italian Communists are still Muscovites,'' insists Ruggero Orfei, himself a pacifist as well as a Roman Catholic journalist and author who is said to be a sort of consultant to the Christian Democratic leadership. ''The PCI has never openly acted contrary to the interests of the Soviet Union.
''I admit that in the Communist Party, even in its higher leadership, there is a strong current toward the West.
''But the raison d'etre of the PCI as a party is still international communism.''
On the local level, the PCI has wielded considerable power for several decades. Perhaps ironically, it is in the most prosperous, capitalist cities of the north - Bologna, Modena, Parma, Turin, and others - that the Communists have been most successful in running things.
These cities are considered by the rest of Italy to be models of urban efficiency and well-being. The Communists active there have remained relatively untainted by the scandals that dog most Italian politicians.
''The PCI has an image of being 'Mr. Clean,' '' the Western diplomat remarked. ''It's true that their leaders in Rome live simply, on modest incomes. Recently, though, a PCI politician in Turin got caught with his hands in the till. It does happen - even to them.''
San Giorgi at Christian Democratic headquarters is reserved in his praise of Communist local governments.
''They tend to discourage private enterprise,'' he claims, ''and to hand out privileges to their own party members. In Naples, where economic conditions are much worse (than in the north) they weren't able to solve the problems that arose, and their local government fell.''
This has been a year of transition for the PCI. Enrico Berlinguer, who became party secretary-general in 1972, passed on in June.
Huge crowds came to his funeral, and the general feeling in Rome is that he was an exceptionally honest and dedicated leader.
Whereas Mr. Berlinguer was characterized as an idealist, his successor, Alessandro Natta, is described as a pragmatist.
''Berlinguer had many active Catholics around him,'' the Western diplomat said. ''Natta is more secular. Natta had been a kind of eminence grise during Berlinguer's days. At first it was thought that he was only a transition leader, but now he is firmly in the saddle.''
In a recent interview in the newspaper La Repubblica, Mr. Natta described the Communist attitude toward private enterprise in Italy:
''We favor a system of economic development, of income, investment, and employment. We would support a radical change in the politics of public spending , a cutting of wasteful, unproductive, and unnecessary deployment of funds in favor of investments and fuller employment.''
One point the PCI makes to allay fears of any possible totalitarian takeover on its part is its relationship to Italy's democratic Constitution.
''We invented it,'' quipped Fabio Mussi, the member of the Central Committee who is in charge of information and propaganda, in an interview at PCI headquarters. He was referring to the important role the Communists played in the fight against Fascism and the establishment of the present Constitution after World War II.
''We would always support a multiparty system,'' he went on. ''In fact, we would always want every single party to have a say in the government. Even the smallest parties.''
And what is the PCI's relationship to the worldwide communist movement Mr. Orfei described?
''There is no such thing,'' Mr. Mussi says. ''That is a concept of the Soviets, but it doesn't correspond to any political reality. In terms of some of our national and international policy choices, we are much closer to the Chinese Communists than to the Soviets.
''The Chinese support a policy of detente, of gradual, supervised, and enforced disarmament. They support an active role for nations other than the superpowers, such as China and the European countries. They support the concept of a controlled economy, while at the same time introducing new market policies to liberalize their internal economy. Our positions are very similar to theirs.''
''Italy belongs to NATO,'' he went on. ''And we support this. We in no way question the present European and Western alliances.''
Conservative Italians view such assertions with scepticism, considering them propaganda aimed at winning votes. If this is the case, they are quite successful.
In the elections for the European Parliament last June, the PCI won more votes than any other party in Europe - 33.3 percent of the total votes cast.
In Italian elections, the PCI consistently comes in only a few percentage points behind the Christian Democrats.
But since the 1979 ''historic compromise'' government, in which the Communists played an active role, the margin has widened slightly.
But few deny what the party maintains is its honorable, relatively clean record during the last 40 years of tempestuous Italian politics.
''One American diplomatic observer made a remark which was very wise,'' commented Central Committee member Mussi. ''He said there are Communist parties in Europe which are like little societies within the society. But the Italian Communists - he said - are an integral part of Italian society. This is a very important point to understand.''