About the troops in Germany, i think they stayed after WW2 because of the Cold War, remember that Germany (and Berlin) was divided in 4 under the control of the US, England, France and the Soviet Union, but afterwards, the Soviet Union and the other 3 did not agree at all in the reconstruction of Germany (once again, Cold War), because of this, the US, England and France started a plan for the non-soviet Germany and non-soviet Berlin, and the Soviets did their thing with the rest of Germany, so the DDR (East Germany) and the BRD (West Germany) were born...
So the US troops in Germany was a justified action because of the Soviet Union, of course, that doesn't explain why are they still today, but it explains why they stayed at least until the fall of the USSR and the reunification of the Germanys at the end of the 20th century...









