By Bridget Kendall
Diplomatic correspondent, BBC News
David Miliband believes the Taliban is open to fragmentation
July has been the deadliest month so far for both British troops in Afghanistan and the Nato alliance as a whole, and with terrible consequences for civilian victims in Afghanistan too.
It is perhaps the inevitable result of the International Security Assistance Force (ISAF) taking the fight to the Taliban to try to reduce their ability to disrupt next month's Afghan elections.
But David Miliband's speech at Nato headquarters in Brussels was an attempt to remind both the British public and Nato countries as a whole that this wasn't just a military campaign, it had to be political as well.
"We will not force the Taliban to surrender just through force of arms and overwhelming might," he said.
Trying to win over moderate Taliban leaders and foot soldiers is not a new idea. But what David Miliband seems to be talking about is something grander
"Nor will we convert them to our point of view through force of argument and ideological conviction."
In his view the strategic objective had not changed since 2001.
It was still to deny al-Qaeda leaders and their allies among the Taliban what he called their "incubator of choice" - safe havens in the "badlands" between Afghanistan and Pakistan from which to launch new terrorist attacks elsewhere in the world.
But, he argued, in the last eight years the insurgency which Nato was fighting had changed.
It had become broad and adaptable. And the autonomy of its local commanders made them resilient, even when superiors were captured or killed.
Nonetheless, this "wide but shallow coalition of convenience" also made the insurgency vulnerable to fragmentation.
And this, he argued, should be the key to any political strategy - a political squeeze on the Taliban from within as well as from without.
Trying to win over moderate Taliban leaders and foot soldiers is not a new idea. But what David Miliband seems to be talking about is something grander.
The new Afghan government that emerges from next month's presidential elections, he said, should be prepared to work on an "inclusive political settlement" to draw away all those less than convinced about their allegiance to the Taliban and even those who might want Islamic rule locally but were not in favour of a violent jihad worldwide.
New tensions about civilian victims of Nato's military offensives have emerged as a result of the election campaign
So, though addressed to Nato and Brussels dignitaries, this was a speech that the British government clearly hopes will resonate thousands of miles away, in Kabul.
Putting on notice what Britain, at least, expects from a new Afghan government. And, in return, a pledge that foreign troops would not leave while Afghan communities needed their protection, but would not stay a moment longer.
"This is not Britain's fourth Afghan war," Mr Miliband said with some passion. "We are not there for a colony of endless Afghan control."
Instead, he added, appealing directly to his Brussels audience, the Nato alliance had to start really believing in its own rhetoric... that the end aim was "Afghanization".
That is what Afghan politicians want too, of course. But new tensions about civilian victims of Nato's military offensives have emerged as a result of the election campaign.
As the British foreign secretary pointed out, any new Afghan president will be running Afghanistan for the next five years.
Making sure their view of the country's future and Nato's strategic aims coincide couldn't be more important.