Ottawa is planning a "low-key" response to Russia's alleged recruitment of a Canadian naval officer who has been charged with leaking sensitive information to a foreign entity, CTV's Ottawa Bureau Chief Robert Fife reports.

Sub.-Lt. Jeffrey Paul Delisle is facing two charges under Canada's Security of Information Act, and sources told Fife that Russia was the nation involved.

While federal officials could launch a complaint with the Russian ambassador or expel diplomats stationed here, Fife said Ottawa isn't interested in a "tit-for-tat" expulsion battle with Moscow.

"I'm told this will be kept very low-key," Fife reported Tuesday.

"We don't want to poison relations with the Russians, because the prime minister is going to Russia in the fall for an APEC meeting."

Earlier Tuesday, Defence Minister Peter MacKay would neither confirm nor deny that the Russians have been on the receiving end of information that Delisle is alleged to have passed along since 2007.

But Fife noted that Canadian officials have already called chief allies like the U.S. and U.K. to reassure them that a "full-scale security damage assessment" is underway.

It remains unclear exactly what information Delisle stands accused of handing over.

However, the operations centre in Halifax at which he was based handles communications with Canadian vessels, as well as ships belonging to allies including the United States.

The centre is also home to part of an undersea surveillance system that was once operated by the United States Navy to monitor Soviet submarines before it was folded into the Canadian operations.

But if the Russians are indeed the "foreign entity" a Canadian naval officer is accused of leaking secrets to, they were likely looking for intelligence on weapons systems used by NATO, says one espionage expert.

Arne Kislenko, a history professor at Toronto's Ryerson University and an expert in national security, said the Russians would be "very interested" in learning about the "functional intelligence" a man like Delisle would have access to, through his work at CFB Stadacona's Trinity section.

The facility is a naval communications and intelligence operational centre in Halifax.

Delisle would know about not only Canada's weapons' systems, but also those of its partners, such as the United States.

"So in that light, not to say he's guilty because that's not my job," Kislenko told CTVNews.ca in a telephone interview.

"But if the Russians were looking, or anybody else was looking, for somebody who had tactical operational knowledge about Canadian Armed Forces' weapons systems and our relationship with NATO partners, he'd be a pretty damned good guy to go after."

The alleged crimes occurred in or near Halifax, Ottawa and Kingston.

For Canadians who are surprised by talk of Russian spies, given that the Cold War is long over and the western world's attention has turned to terrorists, Kislenko said the reasons for spying on Canada are three-fold.

"Canadians suffer from a chronic naivete to assume we're not important enough to spy on. If I was a spy, Canada would be one of the first places I'd go," he said.

"Who's better plugged in to both the U.S. and the U.K? Who's a member of multilateral institutions and agencies (like) NORAD, NATO, G20, the UN, the list goes on? We're plugged in."

As well, all world powers want to know the military and technological capacities of both their friends and their enemies.

"Even though we're not at war with Russia and relations have improved considerably since the end of the Cold War, from Moscow's perspective the West is still by and large adversarial. We often forget that here," Kislenko said.

Finally, with the Russians allying themselves with international pariahs Iran and North Korea, they want to know what organizations such as NATO may have planned to deal with security threats from those countries.

"The Russians aren't just looking for any old information. They also need to be highly competitive in terms of commercial or industrial intelligence, as well as military technology," Kislenko said.

"Knowing what your enemy has, or even what your friend has, in their arsenal is extremely important."

Canada's reputation safe

According to Kislenko, the facility is the centre of a great deal of information-sharing.

"The co-ordinates of how Canadians do soldiering and the weapons systems that we use, is something that other NATO partners have about us and that we have about them," he said.

But it's highly unlikely that this case will make Canada an international security pariah, given that allies such as the U.S. and the United Kingdom are subject to spy scrutiny as well.

"The reality of the intelligence communities and the military communities is that they know this goes on routinely and they know -- really importantly to this story -- that their own communities are equally at risk," Kislenko said.

"I don't think all of a sudden Canada will become persona non grata in the intelligence community."

With files from Vanessa Greco