Well as "Canada" we have not been invaded by a foreign country but we were invaded by the Fenians after Confederation. Before Confederation the US Colonist invaded Quebec and of course in the War of 1812 we were invaded by the yanks.I don't think it's softness. It's just history. We're a relatively new country and have never been invaded.
Our biggest hostility with a neighbouring country is the softwood lumber dispute with the US