Every innovation in transport technology has geopolitical consequences.
Railroads facilitated the great mass infantry wars that ravaged Europe from 1870 to 1945. Rocketry made the Cold War icy-cool. Air travel gave us Douhet's doctrine of strategic bombing. Cobbled roads built by Roman legionnaires made the Roman Empire possible. And so on.
So: What are the likely geopolitical consequences of self-driving cars and trucks?