Colin Kenny, who heads a Senate committee on national security and defence, believes Canada cannot achieve its goals in Afghanistan and suggests its combat mission, which endes in 2011, should be minimized. (CBC)

Senator Colin Kenny, who heads a federal committee on security and defence, believes Canada cannot achieve its goals in Afghanistan and called on Prime Minister Stephen Harper to use the word retreat.

In a commentary published Sunday in the Montreal Gazette, the chair of the Senate Standing Committee on National Security and Defence said that little progress has been made to bring stability, security and democracy in Afghanistan despite more than $10 billion funnelled to the mission.

"If there were significant signs of progress, then maybe our huge investment would make sense," he wrote. "But that isn't the case."

Furthermore, the Taliban's strength has grown in nearly every part of Afghanistan despite the presence of more than 100,000 U.S. and allied troops on the ground, he wrote.

"What we hoped to accomplish in Afghanistan has proved to be impossible," he said. "We are hurtling toward a Vietnam ending."

"Our troops have performed magnificently against huge odds. But we are not close to achieving our objectives, and there is no sign that we will."

"Prime Minister Harper should do the right thing, and start moving toward a word no soldier likes to hear, but that is sometimes the only intelligent thing to do. That word is retreat."

The Liberal senator, who has visited Afghanistan three times with his committee colleagues, recommended that continued Canadian engagement in Afghanistan should be minimized and that troops should be used for training Afghans, not chasing the Taliban.

Defence Minister Peter MacKay said Kenny's comments do a disservice to the Canadian soldiers, diplomats and aid workers risking their lives in Afghanistan.

"Speaking negatively and making these types of inflammatory comments is simply counterproductive and doesn't help," MacKay said.

"It is really hard to see why we should be putting the lives of young Canadians at risk anymore when we're not seeing the product at the other end," Kenny told CBC News.

And Kenny isn't alone. Robert Fowler, a retired Canadian diplomat who survived an al-Qaeda kidnapping while working for the United Nations in Africa, has also questioned Canada's continued presence in Afghanistan.

"It strikes me as rather extreme that one goes out and looks for particularly complex misery to fix," Fowler said in an interview last week with CBC anchor Peter Mansbridge. "There's lots of things to fix that can be done more efficiently and probably more effectively."

Those opinion shouldn't be ignored, said international affairs expert Steven Staples.

"Senator Kenny is someone who has followed this mission closely," said Staples, president of the Rideau Institute on International Affairs in Ottawa. "I would describe him as the hawkish end of the Liberal party. But now that he has made this assessment and come out publicly calling for a retreat, I think that's very significant."