OTTAWA -- Canada's plodding but dependable CP-140 Aurora patrol planes could prove to be of greater help than fighter jets for an international coalition seemingly starved for surveillance in the skies over Iraq.

Much of the public debate as Canada enters the war against the Islamic State in Iraq and the Levant has been about CF-18s on bombing missions.

But the need for more "eyes in the sky" over Syria and Iraq is something that's preoccupying U.S. military planners and will likely be a major topic when senior coalition commanders gather next week in Washington.

Defence experts say a good chunk of the American military's surveillance capability is still tied up in Afghanistan, despite the urgency of the bombing campaign against ISIS.

The recently upgraded Auroras employ cutting-edge technology that allows them to identify and track targets over a wide area. They were used to great effect in the Libya bombing campaign three years ago.

"What you want, in the way I think this air campaign is unfolding, is persistent coverage," said retired colonel George Petrolekas, a former adviser to former generals Rick Hillier and Walt Natynczyk.

"There is some daylight reconnaissance preparing for the night airstrikes, but there are not enough drones or planes to be persistent."

Having a more consistent view of the movement of Islamic fighters will help slow and eventually turn back their advance, said retired major-general Lew MacKenzie.

Their comments came on a day when some members of the Harper government struggled to clearly define how the military was expected to "destroy and degrade" ISIS.

MacKenzie says many of the easy infrastructure targets, such as oil fields that were a source of revenue for extremists, have already been taken out by previous airstrikes.

"The CF-18s will be used to make sure we don't have more Kobanis happen," Petrolekas added, a reference to the Syrian town along the Turkish border that's in danger of being overrun by Islamic State forces.

Whenever ISIS fighters gather in large numbers -- or try to move between cities -- they'll be hit.

Petrolekas noted Canadian aircraft are prohibited from operating over Syria and restricted to Iraq, where the fighting has been relatively static, which means the fighters could be left cooling their jets until some kind of ground campaign gets underway.

That could be months away and is also a topic to be discussed in Washington next week, according to published reports in the U.S.

In Ottawa, International Development Minister Christian Paradis fell flat in his attempt to deflect Opposition criticism that not enough was being done to help civilians and refugees.

"Targeted military actions will help establish more humanitarian corridors so we can make our people safe," Paradis said before Wednesday's caucus meeting.

Both MacKenzie and Petrolekas were flummoxed by the remark.

"That's bizarre," said MacKenzie. "It's not the way it works."

The only use for "fast jets" in such a scenario would be if soldiers on the ground, running humanitarian supply convoys, were attacked by an overwhelming force.

"As someone who's had to open up humanitarian corridors, I know it takes an awful lot of brave soldiers to either push back the blockage -- or negotiate, negotiate, negotiate," he said.

"Humanitarian corridors cannot be opened from the air."

NDP Leader Tom Mulcair said the government keeps changing its story, and likened the Paradis notion of a humanitarian corridor to throwing spaghetti at the wall.

"That's trying to ex-post-facto come up with a justification for a mission that's already been decided," he said.

It is still unclear where the air task force will be stationed, once it gets overseas.

Prime Minister Stephen Harper confirmed in the House of Commons the planes would be drawn from military air bases in Cold Lake, Alta., Trenton, Ont., and Greenwood, N.S., but he wouldn't say what country has agreed to host them for the six-month -- or more -- deployment.

Kuwait, where the Canadian military has a logistics hub, and Cyprus are the two places most frequently mentioned.

The government is keeping silent because it has yet to negotiate a status-of-forces agreement with the intended country, which is likely Kuwait, said Petrolekas.

That agreement spells out a host of legal and logistical details.

The reason it wasn't negotiated sooner is because the military is reluctant to get too far out in front of Parliament, which only approved military action on Tuesday night.