It was just the one short paragraph that did it. "Pakistan has no interest in a stable Afghanistan that might be friendly with India and demand back parts of Pakistan that used to be Afghan. The Afghan government does not recognise the Durand Line as the border and Afghanistan was the only country in the world not to recognise Pakistan at its creation in 1947."
That brief summary, in a report by the excellent Christina Lamb  of the (now paywalled) Sunday Times, contains volumes about what has become an interminable conflict from which we have no idea how to extricate ourselves. For these are volumes that have been left covered in dust and, except by the odd lonely scholar, were last thumbed in imperial times, when soldiers, chancers and red-faced colonial administrators may have ventured east for the wrong reason -- to conquer -- but often learned a little more about the world in which we never cease to intervene and meddle than do today's politicians, with their tourist and gap-year-level appreciation of the complexities of Asia.
There is an international border between Pakistan and Afghanistan, goes the reasoning. On one side lies a country that is notionally our ally in what we no longer call "the war on terror", while on the other is a state we are supposedly and confusedly trying to help. So why is our ally trying to "look both ways", as David Cameron  put it?
Why do Pakistan's rulers not bring to heel "their" Taliban and "their" Pashtuns, we ask? The latter do know that they are Pakistani, is the assumption; after all, are they not on that side of the border?
None of this is so obvious, however, to the inhabitants of these areas, separated in 1893 by an agreement negotiated by the British diplomat Sir Mortimer Durand, after whom the boundary line is named, but widely viewed  as having been imposed on them by those it affected.
As far as they are concerned, their ancestral lands do not recognise a division that originated merely in the desire to provide the Raj with a buffer zone against warlike tribes and the reach of the Afghan amirs.
Faith in borders
In the west our borders are fixed, in fact and in our minds. The Iron Curtain may be a memory, but Americans are so vigilant about their country's limits that anyone with a Latino appearance in Arizona  is now liable to be stopped and asked to prove that they are not an illegal immigrant from Mexico. The leading members  of the protectionist, inward-looking EU declare, "Ils ne passeront pas." And the coastlines of the British isles have long been its castle ramparts. They announce where nation states begin and end.
Any questions about whether particular groups should be contained within these lines on the map, such as those posed by Spain's Basque "problem" or the United Kingdom's troubles in Northern Ireland, are treated as essentially internal affairs.
Never mind that the territorially defined nation state is a relatively recent invention. They are the units of our geopolitical identity. We expect international frameworks to be built around and on them, and we presume every other country to have the same faith in and attachment to this unit of definition as we do.
But this is blindness in the face of reality for at least two reasons. Many of the world's countries are only a few decades old. The area that is now Pakistan, for instance, may have been home to civilisations when Angles and Saxons were still labouring with wattle and daub, but it was never a "nation" until 1947. Saudi Arabia came into existence only in 1932, after the al-Saud had conquered their rivals in the Nejd and then ousted the Hashemite rulers of the Hejaz. Taiwan has been a separate state only since the Kuomintang were defeated by the Communists in China.
Moreover, the creation of rigid national boundaries often sundered long-established but more fluid arrangements, frequently stranding populations in countries of which they had little desire to be a part.
The province of Papua is in Indonesia because that country considers itself heir to all of the Dutch East Indies; but if its inhabitants had ever had a free choice in the matter, they would certainly have chosen either independence or unification with Papua New Guinea.
The Malay sultanates in the southernmost parts of Thailand and northern parts of Malaysia originally had a tributary arrangement with Bangkok, rather than being part of the Siamese state. Happily, most find themselves on the right side of today's border as a result of a treaty with the British in 1909. The roots of the insurgency in Thailand's south lie in the fact that one historic sultanate does not. As Clive J Christie put it in A Modern History of South-East Asia: Decolonisation, Nationalism and Separatism: "This division provides a classic example of an ad hoc colonial arrangement that has since hardened into a permanent international frontier."
A bad case of patriotism
Hardened is the word, and a tragic one for nations denied their own states by these newly permanent frontiers, as in the case of the Kurds, or most of their historic lands, as with the Armenians. It is also a tragedy for those marooned as persecuted minorities -- in Cambodia, for example, the Muslim Cham, remnants of the old kingdom of Champa, were particularly targeted by Pol Pot's genocidal regime.
But it should also be a word of warning for those policymakers who see borders between countries boldly drawn on maps and assume that they always delineate as sharp a distinction in nationality as the Channel does between the English and the French.
In the areas divided by the Durand Line, no such assumption should be made. There are many reasons why it may be right to say that Pakistan has been looking both ways with regard to the Taliban and even more radical groups operating on both sides of its north-west frontier. But given that a section of its population has doubts about whether it should be part of Pakistan and not, like the Taliban and most Pashtuns, part of Afghanistan -- or even a state independent of both countries -- it should come as no surprise that this should be one of them.
Would these people die for their country? You'd have to work out which country you were talking about for a start -- or if that was a question that even had any relevance to them at all.