In the autumn of 1941, the German army and the Soviet army fought a month-long decisive battle on the outskirts of Moscow, with more than 3 million troops on both sides, heavy casualties, more than a million casualties, and nearly 90,000 people on the Soviet side, including Stalin's eldest son Yakov. Yakov was not a former soldier, and after graduating from university he worked as an engineer at a moscow faculty of civil engineering.
At the outbreak of World War II, in order to prevent his soldiers from surrendering to the enemy, Stalin made a very special order, that is, to prohibit any soldier from surrendering to the enemy, and once a soldier surrendered to the enemy, then they would be directly treated as traitors, not only they themselves would be charged, but their families would also be punished in various ways. Compared with Stalin's policy of punishment, many people still care more about their own lives, and in the face of life and death, many people are concerned about their own lives, and are not affected by the policy of punishment, and directly choose to surrender to the enemy.
After Yakov's arrest, Stalin issued the statement "Why didn't he die in battle", which made it clear that if Yakov was heroically employed, it would become an idol for young people throughout the Soviet Union to learn, and if he was beaten in prison and surrendered to the Soviet Union, then not only Yakov's reputation would be destroyed, but Stalin's reputation as a leader would also be greatly affected. When the Germans offered to exchange Yakov, Stalin suffered, but soon refused, because if he exchanged his son for the German marshal, his reputation would plummet, and his "banner of the communist cause" would be completely tarnished, and he could not do it.
In addition, his son was also deep in the mud at that time, sticking to a stinky water. Under the propaganda of German public opinion at that time, this prince was already a traitorous thief, at least, this public opinion attack in Germany made many people in the Soviet Union believe in this matter, at this time, if Stalin wanted to change him back, it would undoubtedly create pressure on himself.