With every revelation of NSA and GCHQ espionage around the globe, the question of what it means to be an Anglo-American ally in the internet age has become increasingly murky.

Countries that considered themselves close partners on strategic issues have realised that in the world of electronic intelligence they are not just outsiders, they are targets. Germany, France, Spain, Turkey and Belgium are all Nato allies who have sent soldiers to fight alongside American and British troops in Afghanistan, but have discovered that there is little sentimentality about such comradeship in the world of electronic espionage.

All have been the subject of NSA or GCHQ spying, either at the top level, in the form of eavesdropping on leaders and officials, or in the form of bulk interception of the everyday conversations of millions of citizens.

Emerging powers in the southern hemisphere, such as Brazil and South Africa, also found that their partnerships with Washington and London, and their burgeoning status, have not given them immunity against intrusive surveillance.

The trove of documents leaked by Edward Snowden demonstrate that the only significant protection against being a western intelligence target is membership of "Five Eyes", the club of English-speaking powers: the US, UK, Canada, Australia and New Zealand – and even that may not be absolute. Included in the membership privileges is access to huge amounts of data, mostly scooped up by the NSA and GCHQ. And in a club with few other limits on its ambitions, there are strict stipulations against one member spying on another "second party". "Third parties" – the rest of the world – are rated according to usefulness and friendliness, but all are fair game for covert monitoring. For example, Snowden's documents revealed that Australia's spy chiefs had been attempting to monitor the mobile phones of Indonesian president Susilo Bambang Yudhoyono and his inner circle – leading to a collapse of relations between the countries.

The exclusivity of the club and its seemingly cast-iron barriers to new members demonstrate that when it comes to trust between governments, old Anglo-Saxon loyalties trump more modern European and Nato alliances. The newer the technology, it seems, the older the bonds. Other nations, including longstanding partners, woke up this summer to discover just how far out in the cold they really were.

The Snowden files also show that spying among friends brings limited benefits. The intelligence services of closely allied states constantly exchange intelligence on terrorism anyway. Nato partners spent their lives in committees sharing information on the state and activities of their respective armed services. The marginal advantage gained most often takes the form of knowing other leaders' bargaining strategy before they show their hand. Such eavesdropping could help you get the best possible deal from trade or financial talks – as long as you are not caught in the process.

Considering the Snowden files were shared with hundreds of thousands of government analysts with top-secret clearance, up to half a million of them private contractors, Washington was playing a high-risk game. It was perhaps only a matter of time before a disillusioned employee broke ranks. The costs are still being played out, but they seem to range some way beyond embarrassment.

The European Union

While revelations that tens of millions of Europeans were having details of their phone calls intercepted created widespread unease, it took the case of one particular German to create a crisis in EU-US relations. Angela Merkel was said to be livid at reports that her mobile phone had been tapped by the NSA, and called Barack Obama to demand an explanation. The fallout marked a new low in bilateral ties and was hardly helped by the White House's carefully parsed response denying present and future monitoring of the German chancellor, while remaining silent about the past.

"Spying on an important partner like Germany and not only on an anonymous group but on Mutti [Mummy, Merkel's nickname] herself, is very different for Germany," said Eric Gujer, an expert on European electronic intelligence at the Neue Zürcher Zeitung.

Earlier in the summer it had been reported that the NSA monitored half a billion German telephone calls, emails and text messages a month. In September, French media reported that everyday personal calls, 70m a month, were being sucked up and recorded by the US agency.

In October it was Spain's turn, with reports that the NSA had monitored more than 60m phone calls in a month. Madrid summoned the US ambassador to Spain to demand an explanation of the extent of US spying.

The Spanish foreign minister, José Manuel García Margallo, said that if the monitoring was confirmed, it could "lead to a breakdown in the traditional trust" between the two countries.

These affronts to some of Europe's most powerful nations followed allegations that GCHQ had mounted a cyber-attack on Belgacom, the dominant telecoms firm in the EU host nation, Belgium, aimed at "better exploitation" of Belgian communications and extensive wiretapping of EU missions in New York and Washington. The European reaction to the first wave of Snowden revelations in June had amounted to little more than expressions of concern and then silence. This time, as it became clear how far European populations and leaders were affected, the backlash was stronger and more sustained. "This is not just about embarrassment. It's not just a question of calling in ambassadors. I'd be surprised if this goes away," said Bruno Tertrais, senior research fellow at the Strategy Research Foundation in Paris.

"From a French standpoint, recent crises in which we have been involved with the US, in Mali and Syria, have triggered doubts on the reliability of the US as a security partner. The Snowden issue just adds to the feeling of uneasiness."

At an EU summit on 25 October, Merkel and the French president, François Hollande, joined forces to call for a new intelligence deal with the US in which European capitals would have guarantees against American snooping.

"It's become clear for the future that things have to change, and they have to change radically," Merkel said, adding that it was necessary that "trust can be rebuilt". She sent her spy chiefs to Washington to try to lay down some new ground rules. They may be given assurances but membership of the Five Eyes, outside of Afghanistan at least, seems unlikely.

The leaders ruled out a suspension of continuing EU-US talks on a new transatlantic trade and investment partnership (TTIP), but it seems likely that the deeply complex negotiations would be complicated further.

More importantly, the European parliament passed privacy legislation that had been stalled for two years at American behest, that limited the ability of US telecoms companies to transfer European data abroad, under threat of severe fines.

Latin America

The diplomatic costs of friendly fire spying could be as great in Latin America as in Europe. For pure outrage, nothing has come close to Brazil's president, Dilma Rousseff, on discovering her phone calls and texts, and those of her aides, had been intercepted by the NSA.

She cancelled a state visit to Washington scheduled for October and instead went to the UN general assembly in New York the month before to denounce American intelligence as a violation of Brazilian state sovereignty and international law. "Personal data of citizens was intercepted indiscriminately. Corporate information – often of high economic and even strategic value – was at the centre of espionage activity," she told the UN. "Also, Brazilian diplomatic missions, among them the permanent mission to the UN and the office of the president of the republic itself, had their communications intercepted.

"Tampering in such a manner in the affairs of other countries is a breach of international law and is an affront of the principles that must guide the relations among them, especially among friendly nations. A sovereign nation can never establish itself to the detriment of another sovereign nation. The right to safety of citizens of one country can never be guaranteed by violating fundamental human rights of citizens of another country."

Rousseff proposed a breaking up of the architecture of the global internet, building an independent network that would bypass the giant American internet corporations implicated in the espionage scandal.

Mexico too, has discovered its present and previous presidents have been NSA monitoring targets despite the country's close co-operation in the battle with drug cartels and illegal immigration. Both are key security concerns for the US, which would immediately and tangibly suffer from a withdrawal of any degree of Mexican collaboration.

The G20

The new summit of the 20 nations group is supposed to bring together established and emerging powers to provide a better steering committee for the world than the rich country club of the G8 and the cabal of second world war victors in the UN security council. However, when Turkey and South Africa came to the G20 jamboree put on in London in 2009, it appears they were paying an unwitting price for their invitations. They were having their pockets picked by GCHQ.

The Turkish finance minister and up to 15 officials in his party were targeted for surveillance. Before the South Africans even arrived, their foreign ministry and London high commission had already had their computers penetrated to extract briefing notes for delegates. Meanwhile, the security on delegates' BlackBerrys was penetrated to monitor their email messages and phone calls and an internet cafe laid down for visiting diplomats enjoying Britain's hospitality had been rigged by GCHQ to extract usernames and passwords "meaning we have sustained intelligence options against them even after conference has finished".

Turkey and South Africa complained bitterly but the storm passed, apparently forgotten. There are other pressing and immediate concerns that required working with Britain.

But while pounds and pence were not lost, it seems likely that the less tangible soft power, in the form of trust, seeped away from the eavesdroppers. In realpolitik terms, it sometimes seems a superfluous commodity, but when striking a global deal depends on a handful of leaders in a room against a deadline, personal trust can go a long way. Its loss is hard to measure, but that does not make it any less substantial.