Prime Minister Justin Trudeau and Defence Minister Harjit Sajjan deserve praise for acting promptly on the decisions at last week's NATO summit.
Early next year, a rotating Canadian battle group of 450 will arrive in Latvia to defend – if need be – that country's borders. There will be similar NATO forces from other countries in Poland, Lithuania and Estonia.
The news that the Canadians will be coming to Latvia has apparently been welcomed already, though Latvians of ethnic Russian origins may have some ambivalent feelings. The Russian news agency TASS has already reported a peace protest against the Canadian presence still several months away.
In the 2015 election, the federal Liberals had promised in their platform to commit themselves to "assurance measures" in Central and Eastern Europe, with "an agile, responsive and well-equipped military force" that would "offer international deterrence and combat capability."
Cynics might understandably have expected that the Liberal government once it came to power would be slow to act on these less than "sunny ways" promises, but in fact (perhaps with the encouragement of President Barack Obama) the Liberals are willing to take part in the NATO's defence of Eastern Europe.
The risk of a new cold war, let alone a third world war in Eastern Europe, is small, but Russia's illegal annexation of Crimea, and its thinly disguised subversion of order in eastern Ukraine, shows how willing President Vladimir Putin is to make serious mischief.
To a considerable extent, the NATO forces in Central and Eastern Europe will be sitting ducks. Russia has been moving much of its forces closer to its western borders, and has far more military personnel there than NATO will have on the other side of those borders.
But the risk of leaving a whole set of countries virtually undefended would be most unacceptable. Mr. Putin has no wish to try to attack the military of the United States and its allies, even if some other prospective annexation seems attractive, and even if the NATO forces are few. The Canadian government is showing that it continues to understand these matters.