Jewish soldiers serving in the Polish Army took an active part in the defensive war of 1939, protecting Poland against the German and Soviet invaders. Their graves can be found, among others, in the Jewish cemetery on Okopowa Street in Warsaw. Jewish officers who were captured by the Soviets shared the fate of thousands of their Polish peers.

According to various estimates, between 100,000 and 150,000 citizens of Jewish origin were mobilised in the defence of the Second Polish Republic in 1939. They accounted for 10 to 15 % of the entire conscripted population. Determining the exact losses among Jewish soldiers is very difficult. Estimates range from 7,000 dead to 32,000 killed and wounded and 35-65,000 taken prisoner. The Germans released tens of thousands of Polish Army soldiers of Jewish origin to their homes at the end of 1940, only to place them later as civilians in ghettos and concentration camps. It is estimated that between 1940 and 1943, the Germans murdered around 3,000 Jewish soldiers and non-commissioned officers in Polish Army. 

The fate of the Jewish prisoners of war in Soviet captivity was like that of their Polish fellows. Most privates were sent to penal labour camps, where living and sanitary conditions were tragic. Most officers shared the tragic fate of several thousand Poles, dying in massacres, evidence of which was found in Katyn, Kharkov and Miednoye, among other places. 

Jewish officers of the Polish Army were killed in the same way as Poles. The order to murder more than 21,000 Polish officers – “On the unloading of the NKVD prisons of the USSR and BSSR” was issued on 22 March 1940 by Lavrenty Beria on the orders of Joseph Stalin. The murder of prisoners lasted from April to the end of June. The prisoners were killed with a shot to the back of the head. Many of them had their hands tied behind their backs. Several hundred officers of Jewish origin lost their lives, among them the Chief Rabbi of the Polish Army, Major Baruch Steinberg. The officers of the Polish Army were an intellectual elite loyal to the Polish state, hence they were treated by the Soviets as an element particularly hostile to communism and destined for extermination.