I was wondering if anyone came across an index for geographical advantage of a country with regards to warfare. This index could be based on, for example, Paul R. Hensel's (1997) paper "Theory and Evidence on Geography and Conflict". It could comprise of elements of, for example, geographical characteristics (e.g. island, peninsula, continental) or how geographically central a capital is etc. I could try to make such an index myself, but I don't want to reinvent the wheel. if there is already anything out there.