New figures show there are 104 members of the Canadian military serving with other nations on exchange programs, but National Defence has refused to say how many of them are deployed in front line operations.

Officials are withholding the information even though internal government documents show at sometime in 2015 several Canadian fighter pilots — flying with an unidentified allied nation -—were engaged in combat against the so-called Islamic State.

The heavily redacted records, obtained by CBC News under access to information legislation, are dated April 15, 2015, and asked permission of former defence minister Jason Kenney to deploy a non-commissioned officer with a partner nation.

The Department of National Defence refused to discuss that case, but it was likely a dangerous assignment as a spokesperson said asking for ministerial approval was an "infrequent" occurrence.

When asked for up-to-date information about current exchange deployments, the department refused to provide any detail, citing a blanket of operational security.

"Due to force protection and operational security considerations, we cannot provide identifying information of our members who might be deployed while on exchange," said spokesperson Dan LeBouthillier.

The documents show the vast majority of Canadian exchange troops — 66 — are embedded with U.S. forces.

There are also more than two dozen attached to the British military, and a handful of others occupy positions with Australian, New Zealand, French and Dutch forces.

The exchanges, which are a long-standing practice meant to give Canadians practical experience with other countries, involve all branches of the military — the army, special forces, the air force and the navy.

Combat vs. non-combat

NDP Leader Tom Mulcair says it's unacceptable that the Liberal government, which promised transparency, is refusing to answer the pertinent question of how many Canadians are in harm's way in the service of other nations.

U.S. Army Sgt. LeRoy Bierfreund works with a Canadian instructor during an exchange program and live-fire training exercise at the Canadian Forces School of Military Engineering at CFB Gagetown, N.B. (U.S. Military Photo/Master Sgt. Benari Poulten)

"If Canadians are involved in the military missions of other countries, Canadians have to know that," said Mulcair. "We know what the Americans are doing there. We know what the British are doing there."

Mulcair said if Canada is sending troops to be embedded with those forces "how can Mr. Trudeau continue to pretend this is not a combat mission?"

Canada has up to 850 troops in Iraq, including 200 special forces operators, on its own mission in Iraq. The Liberal government recently extended the deployment until the end of March 2019.

Both the current Liberal government and the previous Conservative government have said the elite soldiers on the ground are advising and assisting Iraq's forces, and open fire on extremists only to protect civilians and allies.

The NDP say that constitutes a combat mission.

NDP Leader Tom Mulcair says it’s unacceptable that the Liberal government, which promised transparency, is refusing to answer how many Canadians are in harm’s way in the service of other nations. (Adrian Wyld/Canadian Press)

Steve Day, a former special forces commander, says he doesn't understand why the government simply doesn't come out and say the country is involved in a "low-intensity conflict" alongside its allies.

"Politicians do not give the Canadian public enough credit on why we have to do certain things," said Day, a retired lieutenant-colonel and head of the private security firm Reticle Ventures Canada.

"I think if they gave the Canadian public a bit more credit, they wouldn't be afraid to say combat. They don't have this debate in any other leading Western democracy."

Washington, under former president Barack Obama, parsed its words carefully when it came to military operations in Iraq, sending in special forces and using similar language about advising and assisting local forces.

Since the election of U.S. President Donald Trump that rhetoric has largely been jettisoned and the U.S. has openly acknowledged deploying troops in Syria to aid in the campaign to unseat ISIS from its de facto capital in Raqqa.

National Defence acknowledges Canadian special forces are eligible to serve "where opportunities exist" with other militaries on exchange, but refused to disclose how many, if any, are involved in U.S. operations in Syria.

And spokesperson Dan LeBouthillier, who declined to offer specifics about the current exchanges, recently drew a sharp distinction between the activities of Canada and its allies.

"Canadian Armed Forces personnel on exchange with other allied countries staff may be deployed by their host nation," he wrote in an email. "This can include a wide spectrum of activities, from humanitarian assistance to dynamic operations. In these instances, it is not a Canadian mission and Canada is not deploying these personnel. The host nation is."

The documents noted, however, that the federal government has discretion on whether to allow Canadians to serve in another nation's combat unit, noting "each situation is unique."

Political legacy

Mulcair argues the secrecy is more to do with politics than security.

"Justin Trudeau owes it to Canadians to come clean," Mulcair told CBC News. "For our troops to be in harm's way; Canadians have every right to know what's going on."

There was a political uproar in the aftermath of the 2003 invasion of Iraq when it was discovered Canadians were serving in an exchange capacity, even though the government of former prime minister Jean Chrétien had decided to sit out the war.

During that time as many as 100 Canadians served in Iraq with U.S. and British forces.

Former chief of the defence staff, retired general Walter Natynczyzk, served as a brigadier-general commanding 35,000 U.S., British and Australian troops in Baghdad.

Retired lieutenant-general Peter Devlin, who later commanded the Canadian Army, also served in Iraq.

Internal government documents from 2008 show as many two dozen Canadians soldiers worked in the plans division of the U.S. Central Command (CENTCOM) in the run-up to the invasion and a further 35 were under U.S. command in an exchange capacity participating in the 2003 ground campaign.

The former Conservative government, with little fanfare, chose to acknowledge Canadians who fought in those campaign when it approved modifications to the existing General Campaign Star medal. The change meant campaign bars, which used to be attached to the medal, were replaced with theatre or service specific ribbons.