Leading article: A year when the pageantry might not hide the unease

The year we will ring out tonight has been one of the most turbulent, exciting and historically transforming of any since at least 1989, the year of European revolutions – and all from a start that promised little but more of the same.

There is much we already know about the year to come. We know that 2012 will be punctuated by national elections offering fresh opportunities for change around the world. We know that the Arab Spring has sown seeds of great hope and also fear, which will germinate as the months proceed. We know, too, that the United Kingdom will be almost perpetually in the global spotlight, as the country celebrates the Queen's Diamond Jubilee and London prepares to host the summer Olympics.

Within all the known knowns, however, is also a host of unknowns. Take the elections – they are full of uncertainty, even for the most entrenched democratic governments. The US primary season opens in Iowa on Tuesday, with New Hampshire to follow a week later, as the American presidential election year settles into its accustomed rhythm. It is Barack Obama's considerable good fortune that the Republican challenge remains unconvincing.

On this side of the Atlantic, Greece was to have offered the first test of how a European technocracy stood exposure to a disgruntled electorate. Its February election has now been postponed until April, leaving Russia's presidential race in March as the first major contest of the year – and suddenly less of a foregone conclusion than it was even one month ago. The familiar figure of Vladimir Putin may well still return to the Kremlin, but the Russian political scene he inherits will not be the one either he, or his people, or much of the world, expected. There are signs that real change in Russia may be afoot.

By April, the electoral caravan will have moved to France, where Nicolas Sarkozy has to prove that his particular combination of political flair and low cunning can still seduce a French electorate shrouded in domestic gloom and buffeted by the euro crisis. At such times, incumbency is a liability, as a swathe of elections last year showed. Will the Gaullist showman prevail over the Socialist stalwart? And what of the appeal of modern populism, as represented by Marine Le Pen, the daughter of old warhorse Jean-Marie? At once unique and a bellwether for Europe, France's vote will be a measure of things to come.

By summer, the US campaign will be in full swing, but so will jockeying for position before China's 18th Communist Party Congress. The two processes could not be more different: the US battle fierce and open, China's closed and mysterious. But the two victors will, between them, have the power to help to shape the world.

President Obama will be strengthened or weakened by the performance of the US economy and the progress or not of troop withdrawal from Afghanistan. Could he go into the election boasting that the US has fewer troops fighting in foreign parts than when Bill Clinton was President? If he can, what would that say about the continued projection of US power? Meanwhile, in China, 2012 will show whether social stability can be maintained as wealth fans out further from the prospering centres, and growth rates, perhaps, start to stutter.

On this will also depend China's credibility both as a template for developing countries and as a reluctant banker to parts of the developed world. With the prospect of change in places as far apart as North Korea, Central Asia and Latin America, and the consequences of the Arab Spring continuing to reverberate through street protests, the one safe prediction that can be made for 2012 is that it will not be a routine year: neither around the world, nor – given the spectacles to come – in Britain either.

It will be said, and there is truth in this, that the feasts of royal pageantry and world-class sport we can look forward to will sit uneasily beside the gathering evidence of social ferment and self-doubt. Aberration or not, the August riots exposed the discontent that lies perilously close to the surface in many British towns and cities. Bread and circuses, however expertly sold and staged, may not lift the public mood for long without the promise of more solid improvements in the quality of life to come. So far, there is little sign of progress.

That said, as we enter 2012, British politics appears calmer than a coalition government has a right to expect, for all the hidden tensions. All the major parties have an interest in not precipitating an election before 2015. The challenges are social and economic, with the first real impact of government reforms to be felt in April, at the start of the new financial year. The scale of the experiment upon which the Coalition has embarked could then become clear, as could the threshold of voters' tolerance. It is then that the alarmist lobbying must be matched against reality, as the realisation hits home that there are experiments – and there are people's lives.

For all the gloomy outlook, 2012 does not deserve to be written off before it has even begun. And if anything can lift the spirits, it should be the Olympics, the greatest celebration of sport on earth. In a rare feat for a major public project, preparations are on time and on budget. As the Games approach, the country must capitalise on their inclusiveness and accessibility, with events shown everywhere on public screens, unsold tickets distributed to all comers, and the same light touch applied to policing as was evident at the royal wedding. As a showcase for the UK and its buzzing, cosmopolitan capital, the Olympics can inspire the whole country to raise its game. We wish all our readers a happy New Year – and our athletes a bumper crop of medals.