It is in US/Canada's interest to have a shipyard in North America building ice breakers. Even though Finland is a NATO member, if something happens to Finland NATO may need some ship yards elsewhere to build more ice breakers (running 24x7 shifts!) while liberating Finland. Remember NATO (and military in general) needs to plan for all worst cases not likely cases.
The above does not mean the shipyards need to be US/Canada. If they are Finland owned and operated that is fine. So long as the workers and a couple (minor) engineers are local that is enough - in the worst case (Finland's shipyard is taken and all the experts there killed) that shipyard is expanded and has some expertise to build on.
Yes, but the yard is Canadian owned. I suppose it was Russian-owned before.
But the combination of foreign ownership together with exporting know-how, this combination is kind of how one loses an industry to some other country; and then upon that there's that you can't even sell to the country that owns the company because of protectionism on their part.