I found the solution with some playing around
You need to set a new MapRoute BEFORE the default route - see below
public static void RegisterRoutes(RouteCollection routes) {
routes.IgnoreRoute("{resource}.axd/{*pathInfo}");
routes.IgnoreRoute("{resource}.ashx/{*pathInfo}");
routes.MapRoute(
name: "State",
url: "{country}/{state}",
defaults: new { controller = "Home", action = "Index" }
);
routes.MapRoute(
name: "Default", // Route name
url: "{controller}/{action}/{id}", // URL with parameters
defaults: new { controller = "Home", action = "Index", id = UrlParameter.Optional } // Parameter defaults
);
}