[_dps]

Your factual observation is correct, but I don't think the parent is suggesting that the absence of weapons guarantees genocide. I believe the claim is that weapons provide a deterrent to genocide.

To relate to your example: Canada may have merely "gotten lucky" in not yet having had a genocidal leader. If I had to pick among two competing theories:

Theory 1) An armed populace can deter genocide. The observed fact is because Canada hasn't yet had a leader inclined to genocide, or influential enough to accomplish it.

Theory 2) An armed populace cannot deter genocide.

I'd be inclined to believe the first. The policy implications of such a belief would, of course, depend on the general likelihood of leaders prone to genocide. If they are vanishingly rare, then the benefits of deterrence are probably outweighed by the costs of widely distributed arms. The history of twentieth century states leaves this, for me, an open question.

[n3rdy]

Not to mention that an armed United States is a reasonable deterrent that would undermine any attempt at genocide in Canada.

The moment it was clear that the Canadian government intended to begin mass executions, activists from the U.S would start moving weapons and other provisions over the border to assist a resistance. This is assuming that the U.S government didn't send its own military to stop the genocide itself.