I would attribute a peaceful Europe as such more to the rebuilding of post war states, industrial investment, massive state aid & recovery, peace keeping forces, & recalibrated political mindsets that took place before the emergence of the Common Market & eventually the EU.
You seem to have forgotten about the European Coal and Steel Community (1951), GrannySquare, the precursor of the EEC, which became the EU. The EISC was set up with the express purpose of pooling heavy industrial resources across Europe so that no one European country in the 'Community' could start a build up of weapons. I'm not sure why this is being ignored in the attempt to prove that the EU has nothing to do with keeping the peace in Europe.
you will note that it was a European initiative, not imposed by the US.
en.wikipedia.org/wiki/European_Coal_and_Steel_Community
Incidentally, Yammy, reparations are paid by the (losing) country held to be the aggressor in a war, not to them. It was the punitive reparations imposed on Germany after WW1 that led to !WW2. I think you're getting confused with the US Marshall Plan (which European countries which received it used to rebuild their shattered economies; unlike the UK which wasted it trying to bolster up its dying Empire)