I think it's when the majority of your relationship is with only one client. You need to have more than one trading partner, more than one client, in order to hedge against the effects of over-dependence when it becomes used as a tool of coercion.
I don't know where that fine line is, but it does mean that while Canada should still be, say, having the United States as a really important if not primary client in terms of critical minerals, we should be leaning into Europe very heavily, and we've seen the government moving in that direction.