A revitalized NATO is already facing its first test of Russian aggression, on the same day it wrapped up its critical summit in Wales.

Russian agents have crossed the border into Estonia, a NATO country, and detained a police officer, according to the Estonian government.

"We should see it... as a demonstration on behalf of Russia that provocations have started," Estonia's ambassador to Canada told Evan Solomon on CBC Radio's The House.

According to Gita Kalmet, Russian agents wearing no insignia crossed the border at Luhamaa, in southeastern Estonia, jammed communications equipment and threw smoke grenades before abducting the agent at gunpoint.

"It's a very demonstrative and brutal act," the ambassador said. But she was careful and remained cautious about comparing the incident to the situation in Ukraine. She also reiterated Estonia's confidence that they will be protected under the NATO alliance.

"We don't think that the same scenario can be re-enacted in Estonia... because we take the fact that we are NATO members really very seriously," she said.

Canada's response

Canada has already reacted to the incident.

On The House, Foreign Affairs Minister John Baird said: "We're deeply concerned and disturbed by the Russians' provocation. But as the Estonians' president has said, let's not jump to conclusions. Let's work to immediately de-escalate this."

The timing of the incident is critical. It comes on the same day NATO wrapped up its summit and just two days after U.S. president Barack Obama was in Estonia to deliver a strong message of support.

"The Baltic nations are among our most reliable allies in NATO and the commitment of the United States to their security is rock solid," Obama said.

"As NATO allies we will meet our solemn duty, our Article 5 duty, to our collective defence. And today I want every Estonian, and Latvian and Lithuanian, to know you will never stand alone."

The Estonians do not view the kidnapping as coincidental, but Russia already disputes the details.

Russia denies agents crossed the border

A Russian official told CBC News that according to the Russian federal security service, the Estonian officer was detained inside Russia. He was carrying special equipment used for recording or spying and was armed.

This could be the first test for the newly invigorated NATO alliance.

The NATO summit came to a close on Friday in Wales with a promise to protect all 28 member countries, including Estonia, from Russian aggression. It launched a rapid response force made up of a few thousand soldiers that will be able to spring into action within 48 hours to protect members from a Russian invasion.

Canada has not joined this force. In Wales, Prime Minister Harper said it was because the nature and capacities of the force have yet to be defined.

"We certainly indicated we're fully supportive of the concept, recognized the need, and we will be working with our allies in the months to come and with the NATO leadership to define what the response force will look like and what the capacities will actually be," Harper said.

On The House, Baird reiterated that Canada is already supporting reassurance measures in Eastern Europe.

"Canada's actively playing part already in the reassurance measures in Eastern Europe, whether that's in Romania or Lithuania, so we're going to remain an active member in the alliance," he said.

Returning from Iraq

The other major issue on the agenda at the NATO summit was how to deal with ISIS, the Islamic State militants who have seized parts of Syria and norther Iraq. Baird was in Iraq this week, he recounted to House host Solomon. "It was absolutely horrifying to see literally hundreds of thousands of people forced out of their homes."

Baird said dealing with organizations like ISIS is "the great struggle of our generation" and the battle "is not something that will start or end in northern Iraq."