It is a decision that violates both the spirit and the letter of the Parliament motion that led to the country's exit from the Afghan war, the opposition charged.
Less than a half dozen Canadians, most of them with the air force, continue to serve in the volatile region that has been the epicentre of the Taliban insurgency.
The much-heralded end to Canada's five-year guerrilla war in southern Afghanistan produced the iron-clad policy that barred soldiers from taking part in combat operations and being anywhere near war-torn Kandahar province after Dec. 31, 2011.
The date was established in the Parliament motion of 2008.
Even though Canada didn't participate, the previous Liberal government quietly allowed Canadian officers, including the country's soon-to-be retiring top soldier Gen. Walt Natynczyk, to serve on secondment in the U.S.-led Iraq war.
In contrast, the original Conservative government dictate over Kandahar was much stricter, perhaps as a reflection the politically radioactive nature of the issue.
The Privy Council Office was asked in the spring of 2011 to approve an exemption for soldiers "working in exchange positions with allied nations," said a recently released briefing note prepared for the head of the army on March 22, 2011.
The note was obtained by The Canadian Press under the Access to Information Act.
The measure was supported by Defence Minister Peter MacKay.
A spokeswoman for National Defence says the dispensation was granted.
Canadian Forces "members serving as fully integrated members of foreign forces in exchange positions are permitted to be in Kandahar province and to serve in combat roles, as their host units direct them," Lauri Sullivan said in an email.
It took the department several days to answer queries from The Canadian Press about the politically sensitive subject.
Since the exemption was granted, at least four Canadians have served in volatile province, two of them with the Royal Australian Air Force, one with the Royal Air Force and one with the U.S. Army.
NDP defence critic Jack Harris said it shouldn't be permitted and the fact the soldiers and air crew are on a secondment doesn't make any difference.
"I believe it's contrary to the Parliamentary motion," Harris said. "It is a decision of this country that they're not going to participate, and their participation in the combat mission in Afghanistan is ended. That means no Canadian troops."
As the war was winding down and prior to the training mission in Kabul, Prime Minister Stephen Harper was quoted as saying that only a few soldiers would be left in Afghanistan to guard the embassy.
Harris said "people accepted that word at the time" and were let down with the training mission, and now see the exemption.
"This belies whether the prime minister and the government is prepared to stand behind their word," he said.
The military says officers involved in the exchange program gain valuable field experience and usually it is the host nation that extends the invitation.
Each case is evaluated individually by National Defence headquarters staff "to ensure the mission is in keeping with Canadian values, directions and policies," said Sullivan's email note.
The final decision rests the vice chief of defence staff who will sign off on the deployment.
Harris said the continuing combat mission in Afghanistan is clearly not in keeping with Canadian values, directions and policies.
The internal documents show, even before Canadians combat soldiers began boarding transport flights for home in July, military planners were wrestling with several thorny requests, including one of an unidentified major who deployed into Kandahar for 12 months with an American battlefield surveillance brigade.
The unit, with the Canadian officer in tow, eventually took up position along the border with Pakistan and stayed there until July 2012.
A concurrent but separate case involved two non-commissioned soldiers who were slated to deploy with the U.S. 1st Cavalry Division to eastern Afghanistan.
Those troops never visited Kandahar.
At the time, the vice chief of defence staff, Vice-Admiral Bruce Donaldson, signed off on the deployments, pending approval of the new policy, but reserved the right to keep the soldiers back or call them home early if the government didn't agree to the exemption.
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