"Blood enemies from the Soviet period and the civil war now work together in government. Former Talibs already sit in the parliament.
"It is essential that, when the time is right, members of the current insurgency are
encouraged to follow suit," he said.
Marwan Bishara, Al Jazeera's senior political analyst, said there was nothing new about Miliband's proposal.
"It's kind of funny hearing foreign secretary Miliband speaking of this as if it is all new invention," he said.
"In fact, this has been tried since the 1950s. There's no counterinsurgency without a political programme.
"At the heart of it is winning the population. In fact, scaring the population into playing ball, if you will, with the occupier."
Miliband's comments came shortly after Anders Fogh Rasmussen, Nato secretary-general, said he expected the military alliance's member nations to pledge "substantially more forces" to Afghanistan.
Rasmussen said the move would be part of a wider strategy of handing over security to Afghans.
He said he expected the alliance to decide on "a counter-insurgency approach, with substantially more forces" in the coming weeks.
"We can, and should, start next year to hand over more lead responsibility for security to Afghan forces.
"We will do this in a co-ordinated way, where conditions permit, and this will allow us to progressively move into a support role."
His comments reflected proposals by Gordon Brown, Britain's prime minister, who suggested on Monday that a timeframe for handing over security district by district could be drawn up in the new year.
Brown offered to host an international conference in London early next year to set a timeframe for foreign troops to hand over to Afghan forces.
But Rasmussen warned that if Nato were to walk away now, "al-Qaeda would be back in a flash".
"If we want to do less in the future, we are going to have to do more now," he said.
Crispian Cuss, a UK-based defence analyst, said that the comments from the British government were "just posturing" from an administration that had failed to clearly articulate its policy for Afghanistan.
"We have seen talk that Gordon Brown wants a summit in January to talk about the future, but Gordon Brown will not decide the future of Afghanistan. That will be decided in the White House and by the US National Security Council," he told Al Jazeera.
"There is no point in that summit, there is no point in a Nato summit and there is no point in Nato asking European leaders for more troops - the policy and strategy in Afghanistan is dictated from the White House."
The United States is currently considering a request for more troops from General Stanley McChrystal, the senior commander of US and Nato forces in Afghanistan.
The international military mission in Afghanistan has become increasingly unpopular in some of the 42 countries that have sent troops to the 100,000-strong foreign contingent in Afghanistan.
|Miliband said history showed that former rivals could be brought into government[Reuters]
Brown is under pressure from the electorate as British casualties from the war increase.
Opinion polls show an increasing majority of Britons want the country's 9,000 troops to pull out of Afghanistan within 12 months.
Miliband warned that there could be no purely military solution to the resurgent Taliban forces in Afghanistan and called for good governance from Hamid Karzai, who was recently- re-elected as president in a poll marred by fraud.
"This is not a war without end, but success must be based on aligning our military and civilian resources behind a clear political strategy," he said.
Five British soldiers were shot dead earlier this month by a "rogue" Afghan policeman they were helping to train, marking a low point of Britain's involvement in the eight-year conflict.