In April 1940, Peiper accompanied Himmler on trips to the Buchenwald and Flossenbürg concentration camps, followed by a visit to Poland to meet with SS and Police Leader Wilhelm Rediess and Brigadeführer Otto Rasch.
Pada April 1940, Peiper menemani Himmler dalam perjalanan ke Buchenwald dan Flossenbürg concentration camp, diiringi kunjungan ke Polandia untuk menemui pemimpin SS dan Polisi, Wilhelm Rediess dan Brigadeführer Otto Rasch.