Okay, not sure why I am reopening this because I expect that I will just be shouted down and accused of falling for mis-information but ...
Walter Hallstein was never a member of the Nazi party and indeed rejected Nazi ideology.
https://en.wikipedia.org/wiki/Walter_Hallstein
The only "information" I can find to support your theory re Hallstein is on a single website that could easily be accused of mis-representing facts (Also had an interesting article saying that there is good evidence to support that the Earth is hollow). Even so, thousands of people were forced in to the Nazi party just to be able to survive, and it is claimed that Hallstein joined professional organisations that were backed by the Nazi party only so he could carry on being a lawyer. After the war, he was never accused of any "crimes" and resumed his civilian life. England was saved invasion by the Channel and so never had to experience political repression and pressure such that the Nazi's imposed on their own people, and the rest of Europe.
He was not the first President of the EU, he was the first President of the Commission of the European Economic Community. There is no overall president of the EU as such:
https://en.wikipedia.org/wiki/President_of_the_European_Union
He was one of the founding fathers of the EU, along with Winston Chruchill and other European leaders and academics:
https://en.wikipedia.org/wiki/Founding_fathers_of_the_European_Union
You are using unsubstantiated information.