OTTAWA — A highly critical report on a mission in Africa has raised questions about Canada's long-standing reputation as an effective peacekeeper.

Ottawa had little justification for sending military observers and others to a UN mission in Sierra Leone, says a Canadian Forces study on the seven-year operation.

And Canadian soldiers and reservists were so poorly matched to tasks that the British officers in command often had to find them low-level work.

"The problem is seen to be a lack of depth of experience or `operational maturity,' particularly in the case of reservists," says a lessons-learned report, obtained under the Access to Information Act.

"Often personnel without the necessary operational experience have been unobtrusively moved to less demanding positions more fitted to their real skills."

Training to prepare Canada's observers for the mission was so inadequate that they were given instructions on how to avoid landmine -- even though there was no landmine threat in Sierra Leone, says the study.

The problems have remained hidden because operations were in a remote area and involved only about 100 Canadian personnel in total over the years.

"The fact that these were small-scale missions likely discouraged detailed and searching analysis," wrote Lt.- Col. A.F. Robertson, author of the March 2005 report.

The UN first stepped into Sierra Leone in the 1990s to promote peace after an insurrection by the so-called Revolutionary United Front, which ultimately failed.

Canada became involved in 1999 when it agreed to send a commander and military observers to support a UN force made up of soldiers from at least nine countries.

Ottawa also sent soldiers to help train the Sierra Leone army. The Defence Department dubbed the contributions Operation Reptile, which ended in July, and Operation Sculpture, the training mission that continues.

In a recent publication, the Canadian Forces hailed Operation Reptile as a success, saying it made a positive impression on officials in other contributing military forces.

Robertson's report, however, questions whether Canada should even have participated, based on a checklist established in 1994 to determine whether Canadian troops should become involved in such peacekeeping missions.

The initial mandate in Sierra Leone was vague and unenforceable; there was no clear division of responsibilities between military and civilian authorities; the operational plan was "unworkable"; and at least one of the parties -- the Revolutionary United Front -- was opposed to the mission.

These were all contrary to Ottawa's checklist standards.

"The humanitarian disaster in Sierra Leone led Canada's commitment to two tasks, even though neither fully met published policy guidelines," the report concluded.

"In neither case is there any evidence that a review of the prospects of success, a risk-benefit analysis, an assessment of the national interest in the area, or an analysis of adherence to the . . . guidelines, was undertaken."

A peacekeeping school at Canadian Forces Base Kingston, Ont., briefed soldiers poorly for what awaited them in the tiny coastal state in West Africa.

"The cultural briefings were inadequate, and did not effectively prepare them for the social and security environment in Sierra Leone," says the study, based partly on interviews with returning soldiers.

Canada's international reputation as an effective peacekeeper dates from the 1956 Suez Crisis, when then-foreign affairs minister Lester B. Pearson helped broker a resolution.

Many governments have since tried to establish clear rules about which peacekeeping missions Canada should join, said Martin Rudd, a defence analyst with the Canadian Institute of Strategic Studies.

But governments too often ignore the criteria in an effort to help, or to be seen to be helping, when a crisis breaks out.

"The desire to do something often gets the better of them," Rudd said from Toronto.

"The tendency to want to take on so many missions can have serious implications" for military resources.

In addition to the Sierra Leone mission, Rudd cited the example of East Timor, where Canadian soldiers were sent in the fall of 1999 for six months when Australian forces were capable of doing the job themselves.

Canada often joins too many missions abroad, partly because peacekeeping has become part of the country's mythology, says a political science professor at the University of Calgary.

"We've bought into our own press clippings," said Rob Huebert, who is also associate director of the Centre for Military and Strategic Studies.

"We're doing it because we believe it's the Canadian way and peacekeeping is seen as an end rather than a means _ and that just creates all sorts of difficulties for our forces."