Tom Mulcair rose to his feet in Question Period on Wednesday, his question so curt he barely had time to button his jacket before the words were gone.

"How many Canadian soldiers are now in Iraq,'' the NDP leader demanded of Stephen Harper.

The answer wasn't so brief. "Twenty-six today," the prime minister said. But there could be more later based on operational needs, though never more than the 69 soldiers the government agreed to send in the first place, he said, rambling on for a bit.

By Harper's standards the answer was unusually convoluted. But nothing about the government's response so far to the ISIS threat has been bathed in the pure light of clarity: from whether Canada offered or was asked by Washington to do more in Iraq to how many soldiers are actually there.

The opposition parties, of course, are trying their best to exploit that ambiguity.

The issue Wednesday wasn't really about how many Canadian soldiers are advising Kurdish forces in Iraq. The point Mulcair and Liberal leader Justin Trudeau are determined to make is that the Conservatives are hiding their real plans from Canadians — even as their own positions evolve on a near daily basis.

Reporters asked Mulcair Wednesday for how the NDP felt about sending Canadian fighter jets to Iraq only to be told "there's no proposal on the table right now to do that.''

The NDP, he said, believes the focus should be on humanitarian aid.

The Liberals stance has also been fluid, from supporting air strikes last week to Trudeau's statement this week that his party wants to see what the government proposes before making a decision.

It's all about trust, you see.

"The prime minister is intent on going to war in Iraq,'' Trudeau accused Harper on Wednesday. "It's up to him to make that case to Canadians. He hasn't even begun."

"How much are Canadians going to pay for the prime minister's war in Iraq,'' Mulcair followed.

And so it went, back and forth, Mulcair and Trudeau.

'National security of this country'

Is the Harper government prepared to send CF-18 fighter jets to the region?

How long would Canada's commitment be, whatever it is? What is the exit strategy once there? Would Canada take part in air strikes inside Syria.

Will NDP leader Thomas Mulcair oppose a Canadian mission in Iraq? He's playing his cards carefully, too. (Reuters)

To that last one the answer was no.

But Harper didn't duck any of the other questions. Though his responses were all framed around the same basic points: no decision on any additional commitment has been made, when it is there will be a debate in the Commons and there will be a vote.

But no one, he said, should underestimate the gravity of the threat posed by the Islamic State fighters.

"The government and most Canadians have judged that the situation in that part of the world is very serious,'' Harper finally said, his exasperation with the barrage of questions evident.

"And if it's allowed to continue and to fester it represents a very serious danger to the national security of this country. We will work with our partners around the world to minimize those threats to Canadians."

CBC News has learned Harper will announce the government's intentions Friday, one day before the end of the initial 30-day deployment of advisers.

Government sources insist the cabinet has yet to sign off on a specific commitment, though sending CF-18s — as Canada did in the 2011 military intervention in Libya — is one option.

Conservative MPs say Harper told them the same thing at the weekly, closed-door caucus meeting Wednesday morning.

A number of MPs confirmed that the prime minister led off caucus by saying the government is weighing further military action in Iraq, but has ruled out ground troops.

He then told his caucus that the decision will be based on the most effective contribution Canada can make to the U.S.-led effort to stop ISIS.

Harper also said that once the decision is made, Conservative MP will be expected to vote for it in the House.

MPs said no one in the room objected to an expanded military mission, though some pushed for an even more aggressive stand.

The price to pay

Conservative MP Laurie Hawn, a former lieutenant colonel in the RCAF, is in favour of Canadian air strikes.

"ISIS won't be stopped with humanitarian aid. ISIS will be stopped by force,'' he said in an interview. "Victory is defined when we stop ISIS from doing what it's doing."

Great Britain, France and Australia have already signed on to the effort. Belgium and the Netherlands have, too.

It will be expensive. A U.S. think tank pegged the cost of the American military efforts so far at nearly $1 billion, a figure that could rise to as much as $3.8 billion per year if air and ground support operations continue at the current pace.

How much Canada has spent, or will spend, hasn't been disclosed.

Conservatives argue that whatever the cost might be it's far less than the cost of doing nothing to stop ISIS and its relentless campaign of beheadings and religious extremism.

Canadian Foreign Affairs Minister John Baird along with Iraqi Deputy Minister Rowsch Nouri Sharways look at the ISIS positions from a front line bunker in Kalak, Iraq, on Sept. 4, 2014 (Ryan Remiorz/Canadian Press)

But there could also be a political price to pay if the government gets too far ahead of public support for an expanded role in Iraq.

That explains, in part, why Harper is going slowly — building the narrative for a greater Canadian commitment while ruling out ground troops, and arguing that Canada has a moral duty to stand with its allies.

He is also pointing out that Liberals and Social Democrats in other countries support the cause in Iraq, suggesting that Trudeau and Mulcair put their own partisan interests aside.

Harper would no doubt accept a bipartisan approach in Canada. But really, he's just as happy to go it alone. After all, he's done that so many times before.