Can the two Italys become one?

Is Christian Democracy on the way to an irreversible decline in Italy? It would be a bold prophet who read into the future of a party that has governed Italy for the past 35 years, but obviously the loss of 2 million votes in the recent elections combined with a restless mood among the Italian electorate pose a number of questions.

It is significant that while Christian Democracy suffered its worst defeat ever, the Communist Party held on to its positions. The former is still ahead, but the margin is narrowing. Should the Communists manage in the future to reverse the trend, the consequences would be incalculable not only for Italy, but Europe and the Atlantic Alliance as well.

Christian Democracy will now have to pay much more for the support of lesser parties, the Socialists especially, which are needed to form a parliamentary majority. And the country will be more difficult to govern than ever.

Perhaps the electoral upset will have achieved a positive result if it leads to a revision of the country's institutions, the electoral system in particular. There are far too many deputies and senators in Italy representing far too many parties. Italians, despite the challenges of terrorism, have shown their attachment to democracy. The question now is how to make democracy work.

After three decades in power, Christian Democracy is obviously worn out, with negative consequences for the country as a whole. Despite countless government crises, Italy has suffered from much instability. The result is not only that the main problems confronting the country are not resolved, but that an ''unofficial'' or underground Italy parallel to the official one has come into existence.

This parallel Italy is the one that, to overcome stagnation and inefficiency, has gone about running things its own way. It is also, at the opposite end, the Italy that takes advantage of inefficiency and corruption to pursue illegitimate , often criminal, ends.

For years large industries and banks have had their own delivery service because they cannot rely on the government-run post office. They have organized their own transportation facilities, including planes, because of delays in government-run railroads and airlines, often grounded because of strikes.

Parallel Italy is also represented by an extensive clandestine economy that tries to avoid government strictures. Several million Italians produce and sell under the counter and get away with it, thanks to the ''bustarella'' - money in an envelope for officials to look the other way. It is estimated that, if this kind of activity were taken into account, gross national product figures would increase by one-third or more.

Parallel Italy could not survive without corruption, with the administration setting the example. The ''scandali'' involving ministers, officials high and low, even one president of the republic, are an everyday occurrence. The trouble is that ''scandali'' no longer causes scandal.

Lord Acton's saying that ''power corrupts'' applies with particular force to Italy and is the inevitable result of political stagnation. Up to a little over a century ago, Italians lived under foreign rule: Austrians to the north, papal in the center, Spanish to the south and Sicily. To people aspiring to unity and independence, the government was the enemy. Some of that feeling has stuck.

Italy is also the Italy of violence and crime. The Sicilian Mafia and the Neapolitan Camorra have existed for centuries (origin-ally they aimed at protecting the people from foreign exactions), but never have they taken such proportions as today. Their power resides not only in terror but in corruption.

Mussolini had found the continued existence of the Mafia incompatible with his ideal of a fascist Italy and had sent a muscled chief of police with full powers to extirpate it. The chief did his duty, but by digging deeper and deeper into the Mafia's sordid network he discovered ''distinguished personalities,'' including fascist bosses. He had to be replaced and the hunt was abandoned.

By digging deep enough today, the establishment could emerge badly shaken. Recently the government had a few hundred people arrested. The newspapers were full of stories on such sensational dragnets. But it takes much more to uproot the evil influence of organized crime.

For the country to face the problems tearing it apart, official Italy and parallel Italy must become one. This in turn requires political renewal, which cannot be achieved when the political situation is frozen. And the only meaningful change implies Communist participation.

The issue is one of the most delicate confronting not only Italy but also Europe and the Atlantic Alliance.