Iosif Vainshtein was born in 1919 in Baku, Azerbaijan. His parents, Avrom-Moyshe and Ida Wajnsztejn, were natives of Poland who had moved to Azerbaijan during World War I. Since the mother, Ida, had failed to master either Russian or Azerbaijani, the family spoke Yiddish and Polish at home. Unlike his mother, Iosif mastered both of these languages; he would later admit that his Azerbaijani was better than his Yiddish 1. Moreover, he knew some Muslim prayers, and this knowledge was to save his life in German captivity. The family was religious, but this did not prevent Iosif from joining the League of Militant Atheists, a "volunteer" organization set up by the Soviet authorities in 1925.
In 1936, Vainshtein finished school and a vocational school, and began to work at a shipyard in Baku. In 1938, he fell ill with typhoid. After recovering, he received a temporary exemption from military service. During the Soviet-Finnish War (the Winter War, November 30, 1939 – March 13, 1940), he volunteered to serve on the Finnish front, following the example of other workers from his shipyard. He was drafted only in early 1940, but did not see combat, because the war was over by that point. Vainshtein's unit was transferred to the Lower Volga region and included in the 21st Army. On June 19, 1941, three days before the outbreak of the Soviet-German War, the 21st Army was put on alert and sent to the western regions of the USSR. According to Vainshtein's recollections [ibid.], only when their train was bombed from the air near Chernihiv (northern Ukraine) on June 22 did he realize that the war had begun.
In August 1941, during the fighting for the town of Zhlobin (in southeastern Belorussia), Vainshtein was shell-shocked and taken prisoner by the Germans. Having seen the Nazis murder Jewish POWs, he claimed to be an Azerbaijani named Mamed Abaiev. During his stay in German captivity, Vainshtein made two escape attempts, but was caught each time, and brought back to the POW camp after heavy beatings. His third attempt, in 1942, was successful, and he joined a Soviet partisan unit near the village of Shpaniv. The unit arranged a screening for Vainshtein and his fellow escapees. While waiting for the first interrogation, he turned to the partisan who was guarding him and asked him a "naïve" question, in fluent Ukrainian: "Are there Jews in your unit?" He received the reply: "No, we have cast them all out." Thus, during the interrogation he kept his Azerbaijani alias, now calling himself Piotr Abaiev. As Vainshtein would later recall 2, he eventually realized that quite a few of the men in the unit were Jews like him, who similarly concealed their ethnic identity under Slavic names.
In 1943, Vainshtein was seriously wounded in battle – remarkably, not against the Germans, but against the Ukrainian nationalist troops of Bulba-Borovets. With great difficulty, he was evacuated to Moscow by airplane, and spent a long time in hospitals. After arriving at his first hospital, Vainshtein gave his real name and demanded to be registered as a Jew. The officer receiving the wounded partisans exclaimed: "What a yield we have today! First, a Ukrainian who claims to be a Jew, and now an Azerbaijani declaring that he is Jewish!"
After the war, Vainshtein, now a disabled war veteran, worked as a home appliance repairman, and later as a repairman of TV sets. He once again became religiously observant, and began to make donations to the local synagogue. In the 1990s, he immigrated to the USA and settled in Oak Park, MI.