Years ago, when I was in high school and college, the board games Risk and Diplomacy served as wonderful playing fields where I could develop and exercise my tactical and negotiating skills.
One issue that often came up in my forays into international intrigue was how to deploy my limited forces to defend far-flung territories while I plotted to conquer the world.
Such questions of military strategy can be handled mathematically. Charles S. ReVelle of Johns Hopkins University in Baltimore and Kenneth E. Rosing, recently retired from Erasmus University Rotterdam, describe their approach in the August-September American Mathematical Monthly.