Wouldn't that make countries like the USA and Canada extremely far apart because they are both large countries? The distance you would get is the distance from Hawaii to somewhere on the northeastern edge of Nunavut/Newfoundland/Labrador
But which country do you pick the extreme edge of, and which country do you pick the nearest point of? For example, if measuring US<->Canada, do you pick the extreme end of Canada or the extreme end of the US?
For every point in both territories, find the closest point in the other territory. From these pairs of points, find the pair with the largest distance. That distance is your Hausdorff distance.