Afghanistan is not a country. It stopped being one nine years ago, when the very people who now rule the roost in Kabul first took over the city.
Even then, Afghanistan was more of an idea than a country. We knew where the boundaries were, and the location of the battered cities and highways.
But there was no government worth the name, no administrative structure, no secular judicial system and no national services.
For most practical purposes, Afghanistan had reverted to one of those white spaces on early maps, marked "unexplored" or "here be monsters".
That is why it is so dangerously misleading to be talking of a new Northern Alliance government taking over from the Taliban.
Neither movement has, nor ever had, the means or the will to form anything recognisable as a government.
It is also madly irrelevant for western leaders to imply a smooth transition to a broader-based regime, governing with the consent of the people. It is simply not going to happen.
For one thing, the war is not over. Though the Taliban forces are melting, there are bound to be - literally - diehard elements who will fight on.
There are also the uncounted numbers of Arab, Pakistani, Chechen and other foreign volunteers with the Taliban and with Osama bin Laden, who know that if they surrender they will almost certainly be killed.
The land we call Afghanistan faces three immediate perils, all of them frightening.
One is that the Taliban will regroup and fight on as a guerrilla force. The second is that the Northern Alliance will disintegrate into warring factions.
And the third, most awful of all, is that Afghanistan will be engulfed by famine.
Given the startling collapse of Taliban support and morale, it's tempting to dismiss the first threat. But that would be stupidly premature.
The movement still controls large swathes of the country, chiefly in the Pashtun ethnic districts from which it originally sprang.
There is no evidence that Pashtuns are any keener than other Afghans on the Taliban's ruthless brand of religious zealotry, but there is every danger that the Taliban = Pashtun formula could ignite a dreadful ethnic conflict with the Uzbeks, Tajiks, Hazara and other components of the Northern Alliance.
The second great danger, that the Alliance will fall apart, is all too evident from recent history.
Essentially, the ragtag army which now controls Kabul, is the same one which was chased out of the capital by the Taliban five years ago.
There are simmering, murderous jealousies within the leadership, and no sign whatever of any united political strategy.
Some favour the restoration of the king, Zahir Shah. Some want an Islamist state not much different from the one they have displaced. Many are more interested in defending their tribal fiefdoms.
The monarchists have the tacit backing of the west, which could be a double-edged weapon in such an instinctively xenophobic land.
There is a superficial attraction in the idea of assembling a traditional loya jirga (grand council of elders) with the old king at its head.
But after 20 years of savagery, the idea that Afghans are going to shake hands after solemnly agreeing a new system of government is faintly ludicrous.
It also presupposes that the octogenarian Zahir Shah, a man who has by all accounts the gravest difficulty choosing what to have for breakfast, can suddenly acquire a dynamic ability to take decisions.
Lofty consideration of future government, however, is a luxury for the future.
What the alliance must do, as the de facto rulers of Kabul, is to establish and maintain order.
Then, with western help, they must somehow channel rivers of emergency aid to the main cities and into the scattered communities of the wild interior.
There are said to be 7.5m people in imminent danger of starvation, and though such figures should always be treated with suspicion, it is clear that with winter already setting in, there could be a humanitarian catastrophe of biblical proportions.