How would magic change the political map of the world?

There are a bunch of threads so far asking how magic would change X or Y, and the answers always seem to be "in ways we cannot predict," but I'm going to try and be a bit more specific here. <br><br>To begin with, our magic system: magic is fueled by life force. In order to perform magic, you need to either burn your own life force, or burn someone else's (which kills them). The more life force you burn, the more powerful the spell you cast. However, burning life force also drains your body of vitality, so burning too much too frequently shortens your lifespan. Thus, using magic is a tricky balancing act: you want to use enough magic to get the job done without using so much that it cuts years or decades off your life. <br><br>The other important thing to consider is that magic can be fueled by the life force of any living thing: human, animal, plant, fungus, bacteria -- anything with a beating heart or a metabolism can be killed and drained to fuel a spell. <br><br>Considering these factors, how would magic change the political map of the world? There are many countries where religion plays a large role in governance, such as Saudi Arabia and Iran in the Middle East. How would the ability to burn human life force for magical power impact these countries? What about countries with a large Christian population? Would there be any countries that -- against all odds -- manage to avoid succumbing to the temptation to burn humans? <br><br>What about the relationships **between** countries? Magic would give nations a whole new way to threaten and attack one another. For example, a nation that possesses nuclear capabilities -- the capacity to burn a large amount of life force and kill millions -- would obviously possess a large amount of magical power. But how would this impact the relationships between nuclear nations? Would it make war more or less likely? <br><br>How would smaller, non-nuclear nations be affected by the magic system? Would they be bullied around -- magical realpolitik? -- or would there be systems in place to protect them? Would it create a system of magical -- not nuclear -- deterrence? <br><br>How would the existence of magic change the global balance of power, especially if one nation discovered a cheap, limitless way to obtain human life force?