Italians blame shadowy powers for bringing terror to Florence: Politicians, Mafia, Masons, secret services? Patricia Clough in Rome on who benefits from the bombing

AS detectives work feverishly to trace the authors of the Florence bomb outrage, Italians are certain of one thing: someone wants to stop their political and moral revolution. But who and why?

The three young men seen by witnesses near the spot before and immediately after the blast, and whose identikits have been circulated, may well have placed the bomb. But no one imagines they are the brains who coldly aimed to destroy one of the world's greatest art centres, the Uffizi gallery, with its irreplaceable masterpieces; who were prepared to massacre any number of people for their own ends; and who early on Thursday, succeeded in killing Angela and Fabrizio Nencioni, their eight-year old daughter Nadia and their nine-month old baby Caterina, as well as a neighbour of the family.

Explosives experts have identified traces of substances known as pentrite and t4, which they say are components of Semtex, the concentrated Czechoslovak-made explosive preferred by terrorists. The same mixture, they say, was used in other Italian massacres, including the assassination of the anti-Mafia magistrate, Giovanni Falcone, his wife and bodyguards, and in the bomb on the Naples- Milan express in December 1984 that killed 15 people and injured more than 200. These attacks are believed to have been the work of the Mafia, aided, if not manipulated, by sinister, hidden forces in what Italians call 'the State'.

But even without this clue, Italians would still be coming to the same conclusions. For decades, shadowy powers have massacred ordinary people up and down the country. The culprits have never been brought to justice. Investigations have been foiled, derailed and insabbiato - quietly buried - by other shadowy powers determined to prevent the truth being known.

So they are left with only one possible trail: their Latin saying, cui prodest? (whose interests are served?). And the conclusions are: old-guard politicians, the Mafia, Masonic conspirators and the secret services; although different people suspect some of these more strongly than others. Most believe that a combination of all four is behind the terror, for these are the people who have most to lose from the astonishing changes that are sweeping Italy.

The corrupt political class, which had been propped up by the Cold War, has virtually collapsed, and magistrates and police are now free to investigate the terrible deeds that went unpunished under its rule. There are politicians, the thinking goes, who are terrified of trial and punishment, not just for corruption but in some cases for possible involvement in murders, bomb massacres and complicity with the Mafia. Cosa Nostra is deeply alarmed at its bosses and their henchmen being arrested, its supergrasses protected by the government while they 'sing' dangerously, and its worldwide, multi-billion pound drug and arms-running empire threatened as never before.

Then there are crooked Masons, members of illicit lodges believed to have brought together Mafiosi, politicians, businessmen and key members of the police and secret services. Attempts by magistrates to investigate these cases are still being obstructed by the authorities. The notorious P2 lodge, headed by its sinister grandmaster, Licio Gelli, but suspected also of being manipulated by politicians, comprised a network of key people in public life, including the press, which aimed eventually to take power. It has supposedly been smashed, but may be living on in some form.

The secret services have long been suspected of being involved in terrorist-style attacks, and were disgraced some years ago when a former chief was alleged to have plotted a coup. Claims that they have been cleaned up are weakened by the fact that a leading official in the SISME, the civilian security service, is in jail accused of protecting and collaborating with Salvatore Riina, allegedly the Mafia's boss of bosses, and other Mafia figures. The Venetian magistrate Felice Casson, who has investigated some of these crimes, says the secret services are not in themselves corrupt. They just carry out orders. But a police union, which also might be expected to know a thing or two, has demanded that the secret services be dissolved.

These suspicions are far from new. Since the late 1960s, bombs in public places massacred scores of people and injured hundreds. Until the fall of communism, a single strategy could be discerned: to spread terror and a sense of insecurity, thus strengthening the conservative 'law and order' mood in the country. Behind this, it is assumed, were elements of 'the State': politicians, perhaps, and members of the secret services, possibly helped by right-wing extremists.

Then came the Red Brigade: terrorists motivated by a genuine, if twisted and fanatical, left-wing ideology. But disturbing indications have emerged recently that they may, wittingly or unwittingly, have been manipulated by 'the State', especially in the kidnapping and murder of the former prime minister, Aldo Moro. One of the cleverest and most powerful Christian Democrat leaders, he had been working to bring the Communists, suitably domesticated, into the democratic fold and ultimately into government.

Finally communism fell and the East-West stand-off ended, but still there was no peace. A year ago bombs killed Giovanni Falcone and Paolo Borsellino, the two magistrates who knew most about the Mafia and posed the single greatest threat to it. But soon investigating magistrates began to suspect that it had been aided by people in 'the State', who alone would have known about their movements. Someone, the reasoning goes, could have been afraid that they would also find out who gave the Mafia its political protection.

Two weeks ago, there was a somewhat different bomb. The television personality Maurizio Costanzo, who has broadcast powerful anti-Mafia programmes, narrowly escaped a car-bomb attack in Rome. It looked - or perhaps was intended to look - as if the Mafia was out to get an enemy. Now the Uffizi bomb is clearly designed to generate maximum shock, abroad as well as at home.

It comes at a sensitive time. The old system is ending, though some politicians may still control their power networks. The new has not yet emerged. The transitional government, committed to reforms, is composed mainly of technicians and depends largely on opposition abstentions.

But if the brains behind the Uffizi bomb intended to terrify the country into stopping the changes, they have failed. The reaction, in vast demonstrations, in the press and in public life is clear: the bomb is one more reason why the old system must go.

'People aren't scared,' said the proprietor of a restaurant just across the river Arno from the scene of the bomb. 'We Italians are a pretty stable lot really. It is 'they' who are frightened because they are finished. These bombs are just the colpo di coda.' That means something like the thrashing of a dying monster.

(Photograph omitted)