The USA , Western Europe and Russia are at war with radical Islam.
End of WW2 over 16 million Germans expelled (2 million women raped) This happened in Eastern Germany not a strong support for the NSDAP party. According to last legal election they got less then 18 per cent of vote in Eastern Germany.
NSDAP main support was in Bavaria (southern Germany) .
Germany is the most peaceful nation on the planet at this moment in time. Use what was done to defeat the fascist as a template and you will have great success in destroying radical Islam.