You want to look into Geospatial Information Systems (GIS), which is on the technical side of the discipline of Geography. Specifically, you could say that GIS is an applied sub-discipline of Physical Geography that deals in digital cartography. There are certainly professional uses outside of academia that relate to your objectives, as I've occasionally seen job ads from think tanks and government contracting firms looking for GIS specialists.
I am not sure how much there is academically in the way of IR/Security-focused conflict mapping, but I do know from my forays into Geography that there is a sort of political aversion in Geography departments to engaging with anything conflict or security-related. As a result, most academic GIS training focuses specifically on the more politically "comfortable" topics of environmental mapping and public health mapping. That caveat aside, if you want to know more about GIS and its applications, you can check out the discussions on r/geography and r/GIS.
In terms of the less technical side of geography, there are plenty of popular authors (Robert D. Kaplan, Parag Khanna, and Tim Marshall all come to mind) and private research/consulting firms (Stratfor, Jane's, etc.) that use geographic explanations for conflicts and security challenges in international relations. However, research in this vein tends not to be taken all that seriously in academia. People in both Political Science and Geography departments will, for different reasons, likely dissuade you from making arguments in that direction. If you're interested in this line of inquiry, you should check out r/geopolitics and refer to their wiki for resources.
As for resources outside of reddit, FEMA and the UN both have free online courses for using GIS in crisis and emergency contexts. Both are available to the general public, and you might want to look into these in order to learn some basic vocabulary and concepts. I've taken both and would recommend them. There is also a specialization on Coursera from UC Davis that gives a broad overview.