Canada's top military commander and his western counterparts have been taking copious notes on the failures and limitations of the Russian Army's campaign in Ukraine — the first time they've seen their adversary fight a major war in decades.

To say Chief of the Defence Staff Gen. Wayne Eyre was startled by what he's seen would be an understatement — given the size of Russia's invading force, its heavy armour, artillery and airpower, and the reputation the Russians brought into the field.

"Yeah, very surprised," Eyre told CBC News in an exclusive interview this week.

"What we were seeing before the war was an over-estimation of Russia capabilities and willingness to fight, and perhaps an under-estimation of the resistance the Ukrainians forces would put up."

The apparent inability of the invading army's infantry, engineers, tanks, big guns and fighter jets to work together ("combined arms" in military jargon) was one of the biggest surprises, Eyre said.

Most people have seen by now the drone footage of tank columns caught in the open being blown away, the social media video of Ukrainian farmers capturing mobile guns. Stories of logistics trucks running out of fuel and ill-fed Russian soldiers tell western commanders a lot about the adversary they might have to fight.

Russia's problems include poor military logistics and lax equipment maintenance, said Eyre. He was quick to add that the valiant defence put up by Ukrainian troops — even when surrounded, as they are in Mariupol — has been the biggest factor frustrating the Russian advance.

"We knew the Ukrainians would fight, but boy are they ever. You can see their willingness to defend their homeland," he said. "On the Russian side, a lot of questions about what they are doing."

And Russia has lost significant numbers of tanks, armoured vehicles, helicopters and fast attack jets — equipment that won't be easy to replace or fix due to western sanctions and embargoes.

With the most combat-ready elements of the Russian Army bogged down and being chewed up by fighting on the snow-swept fields and slushy roads of Ukraine, western leaders have a host of questions to consider — along with some nightmare scenarios.

Eyre said we could "quite possibly" be in for a long war, depending on the West's ability to keep the Ukrainians supplied and whether the Russians choose to escalate with even more horrific weapons.

"Warfare is constant adaption," he said. "So, what's coming next? What are the Russians learning? What are they going to change?"

In the short-term, Eyre said, the threat of Moscow launching tanks over the border into the NATO nations of eastern Europe has diminished — but that doesn't mean there is no danger to the Baltic states, Poland, Hungary, Slovakia, and Romania.

"We have to remember we're dealing with a nuclear-armed power here. We have to be very, very careful [about] drawing too many lessons," Eyre said.

"Russia is very committed in Ukraine. That's where its focus is. In terms of a short-term threat, it's diminished. What the mid-to-long term brings is anybody's question. In terms of ground combat power, that threat has gone down. The threat of air attack, the threat of missile attack — perhaps not."

https://www.cbc.ca/news/politics/ukraine-russia-putin-1.6382269