Nothing is more important in the book trade than timing. This is what decides whether a new release is instantly forgotten or becomes a bestseller, capturing the mood of a nation and encapsulating what many people had thought but not dared to express.
Such is the fate of a remarkable memoir by Sir Sherard Cowper-Coles - a British diplomat who has served as ambassador in Tel Aviv, Riyadh and Kabul - about his three and a half years at the heart of the faltering western campaign in Afghanistan.
He arrived in Kabul in 2007, wanting to make the US-led military campaign against the Taliban work. But it soon dawned on him that the tired bureaucratic phrase "challenges lie ahead" disguised a disaster. Western policy was a ship of fools, he believed, being steered by muddled, ill-informed politicians under the sway of ambitious generals.
He used his time to press, first discreetly and then more openly, for a change of direction. The Taliban would never be defeated, he cabled back to London. What was needed was a political process to bring them back into Afghan politics, supported by a regional settlement involving all Afghanistan's neighbours.
It would be an exaggeration to say that Cowper-Coles was a dissident voice in the Foreign Office. He had the support of the then-foreign secretary, David Miliband. But the British military was determined to prove to the Americans - and to itself - that it was an effective fighting force, hoping to erase the record of its poor performance in Basra, in southern Iraq.
So Britain went to war against the Taliban in their stronghold of Helmand province. It was a bad decision, so bad that London did not want to hear from its man in Kabul that its troops were too few and the whole adventure was going nowhere.
After two tours in Kabul, he was called back to London as the UK's special representative to Afghanistan and Pakistan. He had been promised a top embassy as reward for his years of service, but the senior official who made the promise decided to take the job himself. He later found he was being frozen out of key meetings, that his career was suddenly and unexpectedly in the doldrums. So last year, after 33 years of employment, he resigned from the Foreign Office.
Over the winter, in an extraordinary burst of energy fuelled by the twin shocks of the end of his diplomatic career and the break-up of his marriage following an exhausting tour in Kabul (where he worked six weeks on and two weeks off), then a hectic burst of non-stop transatlantic travel, he sat down and wrote Cables from Kabul. Published by Harper Press in May, it has occupied a place in the UK bestseller list ever since.
Though the weaknesses of western policy towards Afghanistan have long been evident, no one who reads this book will now dare speak of victory. While US political culture still insists on a more upbeat assessment, the reality is simple: all that remains is the unheroic management of the departure of US combat troops by the end of 2014.
I arrange to meet Cowper-Coles in London, outside Shepherd's Bush underground station. As I wait for him to arrive, passers-by are gabbling into their mobile phones in almost every language under the sun. It is a well chosen place, swirling with a multi-ethnic and multinational crowd, so many of whom are in London precisely because of a past decision - good or bad - by some British officer or diplomat. As we walk to the small house where he now lives, I want to ask him how he ended up being surplus to requirements at the Foreign Office, but the passion he poured into writing his book seems mostly spent, replaced by a forceful campaigning tone, in which I can still detect some ambassadorial punctiliousness.
"I arrived in Kabul wanting to share the enthusiasm of the military," he says. "I am naturally pro-military and pro-America. Both my brothers joined the army.
"But it soon became apparent that the counterinsurgency strategy they were following was not enough. In the longer run, even if we got the right strategy [in place], it would still not have been enough. The problem is much deeper than simply suppressing the Taliban insurgency."
The endless debates over how many troops to send and when to bring them back - there are 132,000 now, according to the International Security Assistance Force, of which 90,000 are American - seem to be unrealistic at best. President Barack Obama has recently announced a withdrawal of 10,000 troops by the end of this year and a further 23,000 by the summer of 2012.
"General Dan McNeill (commander of foreign forces in Afghanistan from 2007-2008) told me that 500,000 troops would be a good starting point. With 120,000 to 150,000 all we are doing is suppressing the symptoms of the disease, locally and temporarily in Kandahar and Helmand. The great victories we trumpet are nothing of the sort. We are just moving water round a puddle."
While the military were slowly losing control of the country, Cowper-Coles found himself in charge of a growing embassy full of people engaged in "stabilisation". It was a full-time job to co-ordinate the efforts of these people, and as the country grew less stable, they had no time or inclination to meet any real Afghans.
Ultimately, all this effort was mere tactics. And tactics without strategy, as Sun Tzu said in 550BC, are merely the noise before defeat.
There is no evil genius behind the looming failure in Afghanistan, according to Cowper-Coles, just group think and careerism: "an excess of overeagerness to please by officers and officials telling their masters what they thought those bosses wanted to hear".
As the former ambassador puts it, "The road to Helmand is paved with good intentions."
As special representative for Afghanistan and Pakistan, Cowper-Coles tried to influence Washington towards a diplomatic solution, which he believes was Obama's first instinct, even though in his election campaign he promised to fight until victory in Afghanistan.
Finally the White House appears to have got it. Last month, the president acknowledged for the first time, in an interview with the BBC, that there was no military solution in Afghanistan. It was time, he said, "to use the efforts that we've made militarily to broker a political settlement".
These are the words that Cowper-Coles waited four years to hear. I ask him, if his job is now done?
This is only half the solution, he says. "The real question is whether America in general, and Hillary Clinton (US secretary of state) in particular, have the political will and energy to do what it takes to broker a serious peace - internally and at regional level - over the next three years.
"This will require an enormous amount of heavy lifting, with the clock ticking. And of course the temptation on the side of the Taliban is just to wait us out."
Given the ticking clock, Cowper-Coles is now calling for western forces to declare a Ramadan ceasefire this year to get the process moving.
But the US military and the CIA are now killing Taliban leaders at a fast pace, and proud of it. This means that the experienced people who are most likely to accept some kind of deal are being replaced by young hotheads. They need to kill a lot of Americans to bolster their position before they can take the risk of peace.
This is not Cowper-Coles' problem anymore. Taking advantage of his time in Saudi Arabia, he has started work with BAE Systems, the defence company. His move to the arms industry has disappointed critics of the Afghan war who would like him to use his experience to campaign for a lasting political settlement in Afghanistan, if indeed that is possible.
Henry Kissinger, the old oracle of geopolitics who knows something of US military fiascos from his involvement in the ending of the Vietnam War, sees a grim result of the Afghan adventure: a de facto partition, with India and Russia reconstituting the old Northern Alliance in the north, and Pakistan supporting the Taliban. Without an international process, Kissinger warns, "an India-Pakistan war becomes more probable".
Even partition would not be peaceful, Cowper-Coles warns. "The narco-mafia will fight the Taliban hard in the south. Once again it will be the poor ordinary Afghans who will suffer.
"I hope we will broker something more sustainable. But if we don't, then Kissinger may well be right. It will be a sorry result for billions and billions of pounds of wasted expenditure. We will have let down the educated people of Afghanistan, many of whom will just flee the country."
Alas, not for the first time.
Cables from Kabul by Sherard Cowper-Coles is published by Harper Press.