Nova Scotia MP Peter MacKay has been given what is likely the most difficult and thankless portfolio after Tuesday's federal cabinet shuffle, political analysts say — and certainly the most challenging.

Peter MacKay, left, is taking over as minister of national defence from Gordon O'Connor. O'Connor is the new minister of revenue.
(Fred Chartrand/Canadian Press)

The MP for Central Nova was named defence minister in a cabinet shakeup Tuesday, replacing the embattled Gordon O'Connor.

Peter McKenna, who teaches Canadian and international politics at the University of Prince Edward Island in Charlottetown, said most ambitious young politicians would not want to be named defence minister.

"The first thing they might want to ask themselves is, 'Why am I getting this job — is it my competence or is it because I am on the outs with the prime minister?'" McKenna said.

Prime Minister Stephen Harper switched MacKay to defence from the more prestigious foreign affairs portfolio. The two men had been rivals to lead the Conservative party.

As long as Canadian soldiers continue to be killed in the war in Afghanistan, McKenna said, the job of defence minister will be a thankless one.

"It's probably not going to be seen as a stepping stone to obtaining leadership of the Conservative party in the future," he said.

For that reason, McKenna said, the prime minister may have had personal reasons for putting MacKay in the defence portfolio.

"We all know that the relationship between Mr. Harper and Peter MacKay is not that good. I think it may be a little Machiavellian of Harper, because he probably figures it will be very difficult for him [MacKay] to look good," McKenna said.

"I think it works to Harper's advantage, to keep Peter MacKay offside, and to ensure that he doesn't get any positive press."

David Charters, head of the Institute of Conflict Studies at the University of New Brunswick, also believes MacKay will have a difficult time in his new job.

"I think he has the toughest job in cabinet right now, and I think the centrepiece of his job is going to be to sustain support for what is obviously a politically controversial and unpopular operation [in Afghanistan]," Charters said.

MacKay, a former Crown attorney, is being asked to do what former brigadier-general Gordon O'Connor failed to do: explain why the war in Afghanistan is worth spending millions of dollars and losing dozens of Canadian soldiers' lives.

That is a difficult task, Charters said, with an unpredictable outcome.
        
"In Afghanistan you can do all the right things, and the situation can still go pear-shaped because it may depend on what happens in Pakistan," he said.

"There are things outside the control of the Canadian government which may determine the outcome, regardless of how well or how badly a new defence minister does their job."