When Denmark's Prime Minister Helle Thorning-Schmidt squeezed herself between US President Barack Obama and British Premier David Cameron and used her cellphone to take a picture of all three beaming, she faced a torrent of criticism. For not only did the incident take place during the state funeral of South Africa's Nelson Mandela but also, critics pointed out, because her behaviour was unbecoming: world statesmen are not supposed to behave like giggly teenagers, taking "selfies" on their phones. Even Mrs Michelle Obama allegedly shared the distaste: she ignored her husband's snapping gaggle by looking away, grim-faced.
Yet far from being contrite, Mrs Thorning-Schmidt defended her action: the selfie, she told journalists, showed that "when we meet heads of state and government, we too are just people who have fun".
Tasteless or not, the selfie episode neatly concludes a year in which world politicians and diplomats finally came to terms with the electronic age, with both the huge reach and unique mobilising capabilities of the social media, but also with its immense destructive powers.
Political role and reach
Social media online platforms have long been used for political purposes. Popular views expressed on microblogging sites in China frequently play a key role in influencing Beijing's policies. And the wave of revolutions in the Middle East now known as the Arab Spring would not have spread so quickly had it not been for Twitter and Facebook.
But the use of social media has changed this year, in subtle yet profound ways. During the Egyptian revolution in early 2011, only a third of those tweeting were in Egypt itself, and the overwhelming majority of their messages were in English. However, when serious anti-Government demonstrations erupted in Turkey in late May this year, 90 per cent of the over two million tweets generated originated from Turkey itself, and 88 per cent were in the Turkish language. Social media is no longer Western-centric; it is being "nationalised", absorbed into national politics.
And leaders are also increasingly embracing it. That Pope Francis joined Twitter soon after he acceded to the Throne of St Peter in March this year was not surprising. But the fact that he publicly expressed his satisfaction at reaching 10 million followers within a few months certainly was unusual; until now, only movie and music stars admitted to caring about such figures. Either way, the result is that the Pope is now able to address more people in one day than all the previous 265 popes were able to address in their lifetimes.
The reach and mobilising effect of the social media is now also fully exploited by upcoming politicians. Take the example of Italy's Giuseppe Grillo, a former comedian with a criminal record, no previous political experience and a reputation for mouthing obscenities. In the general elections held in Italy in February this year, this "Clown Prince" captured a staggering fifth of the popular vote without a national political organisation and almost no money: voters were attracted by speeches uploaded on YouTube, and outrageous remarks posted on other social websites. Challenging the political status quo has never been cheaper or easier.
And that, in turn, means that existing leaders and established political parties cannot afford to lag behind: all of Europe's ruling parties have diverted money away from holding formal public rallies to beef up their online presence.
Meanwhile, diplomats are engaged in their own stampede to social media platforms. For the first time ever, an ambassador is now able to engage directly with the nation to which he is accredited by talking to people rather than just officials and grandees invited to cocktail parties. And embassies no longer just transmit messages: they interact. "Twiplomacy" - says Mr Tom Fletcher, the British ambassador to Lebanon and one of his country's gurus on the topic - "comes down to authenticity, engagement and purpose. Twitter is more raw, more human than normal diplomatic interaction".
The US State Department estimates that by the middle of this year its employees were already in "direct communication" with more than 15 million people worldwide. The State Department's Facebook page has attracted 443,000 "likes", despite the fact that its contents are neither that revealing, nor that entertaining.