NATO cannot succeed in Afghanistan with its current number of troops and should enter into diplomatic negotiations with the Taliban to end the conflict there, a former Canadian ambassador to NATO says.

Gordon Smith, currently director of the Centre for Global Studies at the University of Victoria, told CBC News on Thursday that the alliance would need significantly greater numbers of troops to bring peace and stability to Afghanistan through military force.

"I think that if we, or particularly the NATO alliance of which we are a part, maintains the status quo, I don't see in any way that victory is possible," Smith said.

"I just don't see that we are on a winning track."

A U.S. expert told Smith that NATO might be able to win a military victory in Afghanistan if the alliance had closer to about half a million troops.

NATO, which is leading the International Security Assistance Force, a coalition of forces from 37 countries, has about 37,000 troops in Afghanistan. Canada has more than 2,000 soldiers there as part of ISAF.

"With the present level of troops there, we will just never succeed," he said.

Smith, along with a team of experts from across the country, released a report Thursday that recommends that NATO isolate elements of the Taliban from the extremist group al-Qaeda and try to persuade them to join the political process.

The report, Canada in Afghanistan: Is it Working?, suggests that NATO work with the Pakistani government of President Pervez Musharraf to persuade the Taliban to abandon the international holy war fostered by al-Qaeda.

It says the Pakistani government could work with the Pashtuns in northern Pakistan and southern Afghanistan to bring stability to Afghanistan. Pashtuns are Afghanistan's dominant ethnic group.

It is in the interests of Pakistan to have the conflict in Afghanistan end, he added.

"It's worth trying because we don't really have better options," Smith said.

"What we have suggested in the report is that ultimately a political resolution is necessary and that means talking to at least parts of the Taliban that aren't prepared to fight to the bitter end."

Smith, deputy minister of foreign affairs from 1994 to 1997, said negotiating with the Taliban is an unpleasant task but he believes it has to be done.

"One has to explore the political solutions, difficult and unpleasant though they may be. I don't have a higher regard for the Taliban than anybody else, but I don't think there is any other alternative but to talk to them."

Smith was the ambassador to the Canadian delegation to NATO from 1985 to 1990.