Regarding German scientists and Operation Paperclip:
It wasn't just science -- Prior to WWII, Germany was the most advanced country in the world, far ahead of everyone else in science, medicine, literature, philosophy, music, art, manufacturing, etc. Germany was also the first country in the world to implement social security safety nets for its citizens, and Germans were considered the most cultured, the most advanced, the most highly educated, and the most civilized people on the planet.
After WWII, with the Americans and Soviets occupying a divided Nazi State and starting their own "Cold War", the race was on to make "deals" with those scientists who were leading Germany's war effort in physics, aerospace and military research, many of whom were "conscripted" into service and had no choice but to serve their homeland. In real terms, these men were all seized and arrested by both Americans and Soviets, and then given the choice to a) either switch sides and work for their new captors in military and aerospace research, or never be seen again. In the case of American prisoners, the additional blackmail of "being turned over to the Soviets to face war crimes charges" were used as incentives to make them cooperate.
In spite of the necessity to come out ahead of the competition, America's hands ended up covered in blood, as more than a few monsters were brought to America and given new lives with all the benefits of citizenship.
If there is a lesson to be learned out of all of this, it is that the most civilized and educated people on earth fell sway to mass psychosis and barbarism when their government became incapable of governing, their economy was destroyed by unjust war reparations and hyperinflation, and their national pride was humiliated on the world stage. Rabbi Kahane was clear in his teaching that the German of the 1920's was more cultured, more educated, more hospitable, and less violent than we Americans are today, and yet when faced with literal starvation and hopelessness did what all human beings will do under the same circumstances: They look for a scapegoat and for someone who will make sense and order out of chaos. America today strongly resembles the German Weimar Republic in terms of immorality, corruption, a ruined economy, and a Fifth Column of leftists working from within to destroy the social fabric. It's a short leap from being an abortion doctor to becoming a research doctor experimenting on live human prisoners of the state. If you think that we are innately different in human nature than were the Germans who embraced Nazism you are wrong.