ROME -- When a Portuguese spy pushed an envelope containing top secret NATO documents across a table towards his Russian handler recently, he confirmed Vladimir Putin’s voracious appetite for western secrets and the enduring appeal of Rome as an espionage hub.

 Frederico Carvalhao Gil was arrested in May as he allegedly attempted to sell secrets concerning NATO military bases, defence systems and communications infrastructures to an officer of Russia’s SVR foreign intelligence service, who was arrested with him.

 The clandestine transaction took place in the Number One Caffè, a modest bar on the unfashionable fringes of the Trastevere entertainment district, in the late morning of Saturday May 21.

 A senior officer in Portugal’s Secret Intelligence Service, the 57-year-old Mr Carvalhao had been suspected of being a mole for some time and was followed to Rome by counterintelligence colleagues when he caught a low cost flight to Ciampino Airport a day earlier.

 On the Saturday he took a tortuous route from a hotel in the central Esquilino district, changing direction and popping in and out of shops to try and throw off his watchers, to his appointment on the Viale Trastevere.

 Around eight plainclothes policemen moved in as soon as the transaction had taken place, the secret documents reportedly fetching a price of 10,000 euros. Mr Carvalhao was extradited to Portugal, where he faces charges of espionage and corruption, at the beginning of June.

 He reportedly came under suspicion in November 2015 after a western intelligence agency photographed him meeting with his alleged handler in Slovenia.

 The Portuguese agent denies selling secrets and has told investigators the cash transaction related to a clandestine export of olive oil, in violation of the western embargo on trade with Russia, according to Expresso, a Portuguese magazine.

 Two young women working in the Number One looked uncomfortable when asked about the incident and said they knew nothing about it. But a Chinese shopkeeper and a woman working in a nearby pizza parlour remembered the commotion. “We thought they were making a film,” the woman said.

 The importance of Mr Carvalhao’s information was underlined by the price paid and the fact the Russians used an “illegal”, an intelligence officer operating without diplomatic cover, and thus vulnerable to arrest when things went wrong. The alleged SVR agent has been identified by Expresso as Sergey Nicolaevich Pozdnyakov, who has been resisting Portuguese efforts to have him extradited.

 “Illegals are used to handle high-value agents… who are often known to the local security service, which watches their movements closely,” John Schindler, an American security expert, wrote in an online publication.

 An intellectual, philosopher and freemason, Mr Carvalhao is believed to have had access to important NATO secrets because of his role as a divisional chief within the Portuguese service, which has been part of the Atlantic Alliance since its foundation. The Portuguese investigation, codenamed “Operation Top Secret”, is trying to determine whether the unfaithful spy also sold the identities of western agents working against Russia.

 It is believed he may have fallen for a secret service honey-trap operation following his divorce.

 Mr Carvalhao’s Facebook page — an unusual appurtenance for a spy — reveals his eclectic tastes. There are photos of Russian churches, Georgian landscapes, and a quote from the Roman philosopher Boethius’ “Discourse on voluntary servitude.” There are also indications of his professional interests: a Youtube link to a video entitled “60 minutes shows how easily your phone can be hacked” and photographs from a conference on cybercrime.

 The fact his arrest was made public has been seen as an indication of western exasperation at the intensity of Russian intelligence activities. “This kind of operation is usually very secret and doesn’t normally come into the open,” said Luigi Germani, the head of an Italian think tank. “One hypothesis is that the Portuguese and other western countries are saying: enough is enough.”

 Rome was a busy crossroads for spies during the Cold War, when Italy’s geographic position and political divisions drew the attention of many of the world’s leading intelligence services. The presence of the Vatican, an influential player in the battle for hearts and minds, was an added attraction for the spooks.

 Vitaly Yurchenko, a senior KGB officer who defected to the US in the 1980s, disappeared while in Rome, reportedly throwing off potential followers during a visit to the Vatican Museum, which had the advantage of being in another country.

 What went on inside the Vatican was also of intense interest to espionage organisations. Felix Morlion, a Belgian Dominican, reported on Vatican goings-on for the CIA over many years, while the rival KGB scooped up secrets by planting an electronic bug in a statue of the Madonna of Fatima. The listening statue had pride of place in the dining-room of Cardinal Agostino Casaroli, for many years the Vatican official responsible for the church’s ostpolitik.

 Lavishly furnished with international organisations and a double dose of embassies – to the Vatican as well as to the Italian Republic -- Rome was a stamping ground for Aldrich Ames, one of the CIA’s most damaging traitors, and for Britain’s John Cairncross, after his identification as the “fifth man” in the KGB’s notorious Cambridge spy ring. While Ames was still busy selling secrets while in Rome, Cairncross was purportedly retired from espionage, enjoying his immunity from prosecution, and working at the Food and Agriculture Organisation.

 “Italy was politically aligned with the west, but the influence of the Communist Party and politicians like the Socialist leader Pietro Nenni, who was awarded the Stalin Prize for Peace, meant the country sometimes oscillated between the two sides,” said Ferdinando Imposimato, a magistrate who investigated the shooting of Pope John Paul II.

 “The same applies today with the war against ISIS. Italy is geographically exposed and tries to pose as a non-belligerent. Numerous intelligence services have an enormous interest in influencing our policies,” he said.

 His view was echoed by Salvatore Sechi, a history professor from Bologna University. “Rome has practically replaced Vienna as the location for international talks,” he said. “At this point it is the capital of corruption and international illegality.”

 One of Mr Carvalhao’s Facebook posts shows a photo of Boris Johnson campaigning for Brexit, and the comment: “The eternal problem is that no ideal of loyalty exists that is capable of sustaining the unity of Europe.”

 The reflection takes on an ironic, prophetic quality in the light of its author’s fate.

 ch-pw