At the start of World War II Russia had been an ally of Germany but Hitler, after highly successful military campaigns in the west, turned his attention to attacking Russia. He conceived Operation Barbarossa and began to build up army divisions to carry out the attack. Barbarossa was launched on 22 June 1941 and the German armies rapidly moved east with the aim of reaching Moscow in eight weeks. Feldman was called up to serve in the Russian army in June and by October 1941 he was totally involved in the battle against the advancing German troops.
Sa simula ng World War II Russia had been isang Ally ng Alemanya ngunit Database, pagkatapos ng mataas na matagumpay na kampanya ng militar sa kanluran, nabuksan ang kanyang atensiyon sa mga atake Russia. He conceived Operasyon Barbarossa at nagsimula sa build up ng hukbo Divisions upang isagawa ang mga atake. Barbarossa ay inilunsad sa 22 Hunyo 1941 at ang German armies mabilis na inilipat sa silangan ang layunin ng umaabot sa Moscow sa walong linggo. Feldman ay tinatawag na hanggang sa pagsilbi sa Russian hukbo sa Hunyo at sa pamamagitan ng Oktubre 1941 siya ay ganap na kasangkot sa labanan laban sa pagsusulong German tropa.