The Canadian military is taking a wait-and-see approach to a massive Russian military exercise scheduled to take place on the border of the Baltic states this summer — but the country it's being asked to protect is decidedly more nervous.

Defence officials in the United States said this week that they will pay close attention to the drills, which are expected to involve between 70,000 and 100,000 Russian troops equipped with tanks, armoured vehicles, aircraft and helicopters.

The exercise known as Zapad, or West, occurs every few years and Latvia's ambassador to Canada, Karlis Eihenbaums, says it is always a nerve-rattling time.

"The previous exercise was not very comfortable for us," he said in an interview. "We were always uncomfortable with these exercises because of the size. It's huge."

The fact Russian troops are practising to advance into the West is even more alarming.

"You cannot feel safe," Eihenbaums told CBC News.

The timing is particularly significant for Canadian troops and aircrew.

The Russian exercise will kick off just as the multinational, Canadian-led NATO battle group in Latvia is fully activated, and as a flight of CF-18s resume air-policing missions over the Baltic.

The first of 450 Canadian troops are expected to deploy to their base near Riga, Latvia, next month, and they will be joined over the summer by hundreds of other soldiers from Poland, Italy, Spain, Slovenia and Albania.

Brig.-Gen. Simon Hetherington (centre) is commander of the 3rd Canadian Division which oversaw the training of the the troops deploying to Latvia. (DND\MCpl Melanie Ferguson)

Eihenbaums said the NATO deployment, coming in the face of the Russian exercise, will make for a time of extraordinary tension.

Some of that strain, at least for Western military officials, also involves the expectation that Russia will upgrade its missile defences in Kaliningrad, a sliver of land tucked between Poland and Lithuania. Moscow is thought to be permanently upgrading its nuclear-capable Iskander ballistic missile systems, which are capable of hitting targets hundreds of kilometres away.

'Tripwire' battalions

The Liberal government agreed last summer to lead one of four NATO battalions that are being deployed in eastern Europe as a check against possible Russian expansionism.

The tiny Baltic countries are members of the Western military alliance and asked for the deterrence measures.

The battle groups have been referred to as "tripwires," much to the chagrin of the army, because in the event of a full-scale Russian military action, they would be quickly overwhelmed. In fact, the U.S. think-tank the Rand Corporation estimated in a 2016 report that the Baltic states could be overrun in as little as 36 hours.

It is that kind of operation that Russian troops will be practising in September.

A spokesperson for the Department of National Defence, Col. Jay Janzen, said every sovereign nation "has the right to exercise its military forces and Zapad falls into that category."

He pointed out Canada will be conducting its own drill at the base in Wainwright, Alta. But exercise Maple Resolve involves just 7,000 troops.

Is there a threat?

Whether the Canadian military believes there's a threat from the manoeuvres on the Latvian border will depend on how Russian troops conduct themselves, said Janzen.

"If the purpose of the exercise is to prepare their troops, it is not a matter of concern to the Canadian Armed Forces," he said. "If they are close to the border and the intent is to send a message, that would be of concern."

The situation would be far less tense, Eihenbaums said, if Moscow invited NATO, or other international groups, to observe the exercise.

"What we would be happy to see is that our militaries would be able to monitor the situation," he said. "It would make this exercise more transparent, as it should be among neighbours if they are talking about mutual trust."