That's a fair bit ancient history; frontier defence was generations ago and has been irrelevant for 100 years, and there was plenty of Nazi and Communist support in Canada and the US (and UK and other European countries). For most Canadians that threat dissapeared in the mid 1800s, and wars are something that happen to other countries overseas.
There have been wars and conflicts somewhere in Europe pretty much every generation, and Sweden, Poland and other countries have been having low level incursions and border tests from Russia continuously since the Cold War started.
We've had soldiers forward deployed for NATO on and off for a long time, but then they came back to Canada and had an ocean between them. For a lot of Europe it's not a hypothetical threat when they share borders or can see them across the horizon. That's only ramped up since the invasion of Crimea and the war in Ukraine, but is why Sweden has such a serious home guard and mass mobilization capability that is intended to stop the Russian in their tracks, not just slow them down. Afaik Sweden and Norway both have a standing policy to attack any unidentified subs in their territorial waters, and why Sweden was able to basically seize that grounded Russian sub with a very rapid mobilization years ago.