nuking Canada; the strategic planning is to sacrifice fewer lives of a sparsely populated country to save the many lives of much more heavily populated areas.
In a wartime situation sometimes the leaders have to make some awful decisions like Churchill did during WWII; instances of sacrificing a few for the benefit of saving many.
Eg one time he ordered 6 French warships to be sunk by British Navy and killed about 1000 French Sailors for a necessary strategic gain.