They said Kabul was secure. Elsewhere in Afghanistan, things were fraught, according to the official version, but in the capital, life was returning to a version of what once passed for normal. Someone forgot to tell the suicide bombers.

Their timing, if not their respect for life, was immaculate. Just as Oxfam and two American think-tanks were publishing pessimistic reports this week on the country's prospects, civilians died during an assault on an Afghan army bus. Four "security contractors" kidnapped while building roads were found to have been beheaded. The people capable of bombing the compound of the Serena Hotel, one of the best-protected sites in a supposedly secure city, had again demonstrated a certain contempt for wishful thinking.

It may have been that sort of thinking that caused Robert Gates, the US Defence Secretary, to call on Germany to contribute more troops to the Afghan theatre in the unending global war on terror. The Sueddeutsche Zeitung said the demand was "unusually stern". The newspaper also reported that Franz Josef Jung, the German Defence Minister, was "equally blunt" - but not in an agreeable way - in response.

Canada has meantime said that it will retire from this sport if Nato does not add to the 37,000 personnel it is maintaining in Afghanistan. The country's President Karzai has decided, for his part, that he does not care for Paddy Ashdown as a UN envoy liable to comment on nepotism and corruption. And London's Times tells us that 1000 army recruits will have their training time reduced by half so they can be "rushed" to Helmand.

A good time, then, to prepare 1800 Scottish soldiers, as we reported yesterday, to do their bit? Perhaps not. Or perhaps, at minimum, the nature of the task ahead could be explained to them? Probably not.

The explanation might be of interest to people other than the squaddies. Are we still maintaining the fiction that the Taleban is al Qaeda, and vice-versa? Do we still propose that the existence of British forts in Helmand prevents terrorist bombings in London?

Are we rooting out the drugs trade, or just doing the decent thing by a fledgling democracy? Are we still pretending to hunt down Osama bin Laden? Or might there be a possibility of future oil and gas pipe-lines in the vicinity? By the way, why is all of this "a mission", and on what legal basis, for the North Atlantic Treaty Organisation? These are, one would think, reasonable questions when the bills, human and financial, are climbing steadily.

Herr Jung's reported response to Mr Gates suggests that Nato's members suffer a certain lack of unity. Germany has more than 3000 service people in Afghanistan. They do not, according to their British and American critics, do much fighting, but it seems their government is content with that. In fact, it appears that Germany's conservative administration regards Afghanistan as a catastrophe, or possibly just as wholly unwinnable, and has told the US to stuff it. Canada may follow.

Britain, for mysterious reasons we have touched on in the past, never takes the same view. UK troops are shouldering a burden on President Karzai's behalf that is bringing the armed forces close to collapse, if you believe retired generals and committees of MPs. Harold Wilson at least managed to tell LBJ, diplomatically, that he would not touch Vietnam with his longest barge-pole. There is no such news from Gordon Brown.

This is, to put it no higher, odd. While other Nato members speak up, Britain has no view beyond reiterating a willingness to shed blood, money and bullets for decades to come. For objectives we cannot state. For motives we cannot admit. That is beyond odd. Karzai's rejection of Ashdown is a case in point. The well-informed say that the former administrator of Bosnia was not surprised to hear that the Afghan administration was not keen. A country with a deep pride and no fondness for foreign proconsuls is also entitled to reject even the appearance of neo-colonialism. But if British troops are putting their bodies between the President and his Taleban opponents, a stiffer British response, as they once called it, might have been expected. Yet nothing.

Instead, 1800 members of Scotland's regiment are prepared, and all the old thoughts are awakened. Mindful of the consequences or not, boys sign up and train for these shooting wars. They are not conscripted. They make a choice. It still seems to me that the old line about "the reason why" is a minimum entitlement. No British minister, to my knowledge, has managed a coherent version of that concerning Afghanistan.

It also strikes me that a distant war-zone with horribly high casualty rates produces consequences, like giant ripples in a tiny pool, within a small country. A deployment of 1800 suggests that Scotland will be contributing close to 5% of the entire Nato force in Afghanistan. The US, while "urging" France and Germany, has promised an additional 3000 marines. There is no difference between a Scottish bereavement and an American bereavement. Compare the numbers, nevertheless.

The US has 15,000 troops in Afghanistan. Their country contains, roughly speaking, 300 million people. So someone in our government decides that 1800 is an equivalent contribution from five million souls for what is, in origin and intent, an American war?

There I go again, with my narrow nationalism. That is not, in particular or in general, my point. We can do the history lessons on the eternal usefulness of Jocks as cannon fodder. Many of those stories are the simple truth. We can remind ourselves, too, that the squaddies are the first to assert their right to do the jobs for which they were trained. Soldiers and I would differ about some of that.

We might agree, though, that in a conflict claiming civilian lives, and in which young people are expected to risk death on the taxpayers' behalf, all concerned are entitled to a few facts. Britain, of all the old imperial countries, understands what wars in Afghanistan can mean. I could tell you, meanwhile, what I believe the "special relationship" between this country and the US has become - colonialism reversed; a historical first - but the time for honesty is past due, surely.

What are we doing? Why are we doing it? Or, more to the point, why can't they, or won't they, answer those questions in plain language?

I suspect Afghanistan is already a debacle. Oxfam and Germany's Defence Minister do not appear to differ from that opinion. But still, 1800 trained and (if you believe it) eager individuals from a very small country are about to be sent halfway around the world to kill and be killed for purposes about which we can still, in honesty, only speculate. Odd would be one word, but not the only word.

No-one's asking, but my choice would be to keep those 1800 at home, or use them in tasks elsewhere in which they can take pride, or give them the answer that was supplied to GIs in Hitler's war. Propaganda, of course, and matched by the Nazis. Still: "Why Do We Fight?" asked the literature. They believed that soldiers had a right to know.