Trying to read anything of significance into numbers is a foolish business, yet it satisfies a deep need. We had a lot of that at the turn of the century, and look where that got us. Still, the panic over the millennium bug did not kill anyone, and the O2 is now a great commercial success, even if the survival into another decade of the Pet Shop Boys, who played there last week, is a puzzle to some of us.
If we must divide years into decades, the one coming to a close really started on 11 September 2001. It might have ended with the inauguration in January this year of a US President who acknowledged that most of the response to the al-Qa'ida attack on America was misconceived – although the apparent attempt to bring down the plane to Detroit on Christmas Day suggests that this story is far from over.
At home, the New Labour decade began in 1997 and ended in September 2008 with the fall of Lehman Brothers. That was a long and tonally consistent period in our national life in which, yes, Britain did get better. But much of the improvement was paid for on the never-never, and it was not until the credit crunch hit home that we realised the extent of self-delusion in it all. Easy to blame Gordon Brown for the mismanagement of the nation's finances, but we mostly went along with it.
Those two ways of looking at the past approximate decade offer clues to what Marxists always used to call "the coming period". At the global level, the new decade is already moving beyond the counterproductive simplicity of the "war on terror". This newspaper this year became the first to call for the military intervention in Afghanistan to be brought to an end, which would wrap up the leftover business of an earlier phase. Toppling the Taliban when they refused to surrender al-Qa'ida's leaders was justified, but increasingly our mission there has lost its way and the best way of honouring our brave soldiers is to bring them home. Whether or not the young man on the Detroit flight shouted "Afghanistan", there will be a hangover from 9/11, and the response to it, for years to come.
And, whatever the rights and wrongs of Barack Obama's Afghanistan policy, the new US President has an approach of engaging with the rest of the world that is one of the best reasons for hope. His patient multilateralism will help to deprive jihadists of the combatant status they crave, and start to drain the swamp of anti-Americanism in which their ideology breeds. And that means that the world can move on, to address other urgent challenges. Above all, the threat of climate change. It turns out – it is obvious in retrospect – that this month's Copenhagen summit was the start of a process rather than the end.
For so long it had been presented as the end point of a complex negotiation that its relative failure seemed decisive. In fact, it was, as Churchill might have said, the end of the beginning. That is a phase that has taken too long and advanced not far enough, but even the full green wish list would have been only a platform on which to build. And at least, as we said last week, we understand China, the new carbon superpower, better now.
Domestically, we face an important political choice in 2010. An election that will mark not the dawning of a new era of optimism but the gathering dusk of a long period – possibly as much as 10 years – of austerity. We face, therefore, a large strategic choice. In seeking to close the gap between the Government's revenues and spending, should we put the emphasis on raising taxes or on cutting spending? Plainly, whichever party wins the next election will have to do both, but a different tilt over 10 years could take this country to two very different destinations.
It should be clear that this newspaper would prefer to see the extra resources devoted to public services over the past decade locked in. Some of that money could be spent more wisely, but the improvement in the NHS and in many, many schools and universities are real and precious. The Independent on Sunday would urge the nation to accept European levels of taxation in return for European levels of public welfare, and we wonder whether David Cameron will get through an election campaign without spelling out the consequences of his intention to cut spending more deeply than Labour.
Who knows how long the new decade will really be? At least we have a good idea of the choices that face us and the world.