Weikersthal's 35th Division fought in the battles of Białystok–Minsk, Smolensk, and Vyazma, the three major battles of encirclement on the Eastern Front, in which German forces captured over 1.2 million Soviet prisoners. At Smolensk, Weikersthal was awarded the Knight's Cross. In intense fighting against determined Soviet troops, the German military became increasingly brutalized; a "no-prisoners mentality" became predominant among the 35th Division, which executed Red Army prisoners and shot Jews in reprisals. David Wildermuth notes that Weikersthal's position on prisoner executions was one of "silent acquiescence," and his stance on the murder of Soviet Jews "[lay] between silent acquiescence and undocumented approval."