Italy is gripped by four overlapping crises, the outcome of which will affect the peace and security of nations all along the European coast of the Mediterranean.

The political crisis, the fall this week of Premier Giulio Andreotti and his minority Christian Democratic government, has grabbed the headlines. But the fall of Andreotti, already engaged in the tortuous process of trying to form a new government is a symptom and not a cause of the malaise here.

Italians are no longer performing economic miracles. They are wrestling with the worse inflation and highest unemployment of any developed western country. The lengthening lines of jobless have brought Communist-led workers into the streets in recent weeks and forced the Communist politicians to withdraw their support from Andreoitti. Since Italy is heavily dependent on foreign trade, the combined stagnation-inflation throughout the West adds to Rome's woes.

Beyond this is an endemic social problem, a governing machinery dominated by Christian Democrats that displays vitality only in lavishing state funds on its clients. In private, a key minister, fresh from an institution with a world reputation for efficiency, fumes to an old friend:

"I must deal daily with a certain other ministry. I can't reach anyone there after 11. I spend all my time trying to get a decision, pushing papers."

A Communist union leader talks derisively of welfare cheating. "There are villages in the south," he asserts, "where for every one aged person on a legitimate retirement pension, there are 100 drawing fantastic disability pensions. We have people who are said to be disabled with blindness driving buses."

Finally, there are an estimated 5,000 young men and women, mostly on the extreme left, but some from the far right, sowing an anarchic terror with shootings, bombings and kidnapings. Thanks to an inhibited, clumsy and ineffective police and judicial structure, the perpetrators of seven political crimes out of eight are never even identified, let alone caught.

So a leading Rome newspaperman from a famous liberal journal has bought a .38 Smith and Wesson. "It won't help if they want to kill me," he says. "But if they only try to beat me with a lead pipe, perhaps I can chase them off."

These inter-linked crises and the attempts to resolve them all have parallels in Portugal, Greece and Spain. Italy's actions - or lack of them - will play a major part in their fate, too.

Despite Italy's gloomy perspective, this is a nation of astonishingly ingenious, flexible people whose capacity to survive and absorb has been displayed for two millennia. Near the Coloseum, there are modern apartments in a Renaissance palace built over an ancient Roman theater, all blending into a splendid whole. For all the contradictions, Italy is a land where opposites are synthesized harmoniously.

So it is startling for an outsider to be told by Giorgio Napolitano, the Communist Party Politburo member responsible for unions, that "we are for zero wage increases in real terms to increase employment and investment." No banker could ask more.

It is just as unnerving to hear Aurelio Peccei, an adviser to multinational corporations and world-famous management consultant, declare: "We are lucky to have this kind of Communist Party," and to praise the relatively efficient Communist administration in some towns.

The Communists, the second largest party here, had engaged in a remarkable collaboration with Andreotti that even produced a few results during his 17 months in office. Communist support enabled Andreotti to impose at least enough economic restraint to convert a frightening balance-of-payments deficit into a surplus, strengthen the lira and thereby slice six points from the 22 per cent rate of inflation.

Even more unusual are the close ties between conservative Christian Democrats and the Communists in fighting terror. Ugo Pecciolio, the Communist "shadow minister" for these matters, quotes exactly the same estimates for the size and composition of the terrorists as the government's interior minister, Francesco Cossiga. The Communist even speaks of "red" as well as "black" terror, and he and Cossiga are sometimes linked in the graffiti the terrorists spray on walls.

Partly in reaction to the totalitarianism of Mussolini, Italy has demonstrated an unwillingness to arm its police with either the weapons or laws needed to fight the killers. Only now are the police getting rubber bullets and gas to control riots, armored cars and rifles with laser sights for night firing.

The Christian Democrats have prepared several laws that will make the prevention and detection of crime easier. Whether or not they are passed, on minister observes, "depends on the measure of the political role accorded by the Communists; after all, they must protect themselves from their left."

This is the nub of the political crisis. The Communist leadership withdrew its support from Andreotti largely because the leaders were being pushed by their ranks and by smaller, rival groupings. The Communists are insisting on Cabinet posts to come back, something no Christian Democrat will concede and something the Communists do not really expect now. Whether or not they should be given an increased or decreased say in decision-making is the immediate issue here.

A tough, smart, hard-working group of younger Christian Democrats, about 100 of the party's 263 deputies, is calling for an end to collaboration with the Communists and insisting they must be confronted. These ambitious men, mostly in their 30s and 40s. are typified by Massimo de Carolis.

At the personal level, he fears that a new stronger pact will cement the party's old-guard leadership in power forever. On a border scale, he sees each agreement brining the country closer to a Communist takeover.

"In the long run there are only two different solutions," de Carolis says, looking impatiently at his watch, a man in a hurry. "Either agreement with the Communist Party or a clash. The first case is the way to arrive at the hegemony of the Communist Party. We can't avoid the clash if we don't want to become a Communist country," he says.

Views like these have evidently had great influence on U.S. Ambassador Richard Gardner. Men like de Carolis are described in some embassy circles as "Italy's hope of the future." So Gardner went back to Washington for "consultation" the week before last and the State Department issued a warning against Communist participation in Italy's government.

Nevertheless, many conservative Italians, notable men highly regarded in Washington, believe the intervention was a clumsy mistake. One internationally known figure with impecable conservative credentials said sadly, "Gardner has compromised his mission."

Italians, like most people, are far more sensitive to their own politics than those of others. They have trouble understanding why politicians in Congress or the vocal views of Italian-Americans should influence U.S. tactics so heavily.

Conservative Italians who have worked for compromise with Communists fear that the U.S. stance will strengthen Communist hardliners, far more at home with Moscow than with Western-oriented policies. Leading figures say they cannot understand how Washington's posture squares with the statements President Carter made as a candidate. They cite, for example, his Playboy interview in which he said:

"As far as Communist leaders in such countries as Italy, France and Portugal are concerned, I would not want to close the doors of communication, consultation and friendship to them. That would be an almost automatic forcing of the Communist leaders into the Soviet sphere of influence."

At the superb palazzo housing the U.S. embassy here, visitors can obtain a collection of Carter administration statements, all expressing continued opposition to a Communist role. Yet, Italians are puzzled by the omission of Carter's observations while he was running for office.

The Washington position has been applauded by deputies like de Carolis, and no one here can say flatly that creeping collaboration will not lead to a takeover along the lines of Czechoslovakia in 1948. But this is a distinct minority view. Most Italian leaders, right and left, believe there is no solution to Italy's rooted problembs without consensus politics, without some form of Christian Democratic cooperation with Communists.