Ratzinger’s family, especially his father, bitterly resented the Nazis, and his father’s opposition to Nazism resulted in demotions and harassment of the family. Following his 14th birthday in 1941, Ratzinger was conscripted into the Hitler Youth – as membership was required by law for all 14-year-old German boys after March 1939 – but was an unenthusiastic member who refused to attend meetings, according to his brother. In 1941, one of Ratzinger’s cousins, a 14-year-old boy with Down syndrome, was taken away by the Nazi regime and murdered during the Aktion T4 campaign of Nazi eugenics. In 1943, while still in seminary, he was drafted into the German anti-aircraft corps as Luftwaffenhelfer. Ratzinger then trained in the German infantry. As the Allied front drew closer to his post in 1945, he deserted back to his family’s home in Traunstein after his unit had ceased to exist, just as American troops established a headquarters in the Ratzinger household. As a German soldier, he was interned in US prisoner of war camps, first in Neu-Ulm, then at Fliegerhorst (“military airfield”) Bad Aibling (shortly to be repurposed as Bad Aibling Station) where he was at the time of Victory in Europe Day, and released on 19 June 1945.
From Benedict’s Wikipedia article: