That's a great question - but to clarify, are you thinking of a specific pogrom in 1917? Because pogroms were a huge problem during the Russian Civil War, which primarily took place between 1918-1921. The war was a struggle between the forces of the Bolshevik (Communist) party that had seized power in the late autumn of 1917, also called the Reds, and the White forces who represented all non-Communist groups working together. During this war, between 50,000 -200,000 Jews were killed in pogroms. Previous pogroms in the Russian Empire, including the most famous waves in 1881-1882 right after the assassination of Russian tsar Alexander II by radicals, and from 1905-1907 during the Revolution of 1905, came during periods of social upheaval. People directed their anger towards Jews for a variety of reasons. Pogroms usually consisted of Jewish buildings and homes being looted, Jewish people being beaten up, and in some cases, women being raped. There were cases of deaths, but they were not the norm - they were the exception. Russian police forces would eventually step in and calm the people carrying out pogroms down, which helps to explain their limited nature. (The police did this because they did not like disorder, not because they cared particularly about their Jewish population.) Then the Civil War came. The country was being fought over by two opposing forces.With no single centralized government, it was more difficult to limit outbreaks of violence with police intervention. In areas controlled by the Red Army, however, pogroms took place much more infrequently and those involved were punished (most of the time). In the White-controlled territories, however, antisemitism became one of the few things that linked together people in the army. The Whites did not have common goals, only a common enemy - the Communists/Reds. So they struggled with morale. During the same period, antisemitism was rising again, as it usually did in Russia during a period of upheaval. The civil war caused food shortages and price gouging, and since Jews were often in positions as traders and shopkeepers, they bore the blame for these economic trends, even though they did not cause them. Some White generals started encouraging anti-Jewish violence as a way of uniting their troops. Rather than limiting violence, they pushed for more, which pushed pogroms much further than they had gone before. This, combined with a general upswing in brutality that is common in civil wars, led to Jews being killed in much larger numbers than ever before during pogroms. White forces would not punish people who participated in pogroms, so this behaviour began to be seen as more acceptable. It was also an excuse for massive looting - sometimes White forces lost battles because they arrived too late, weighed down by all the loot they had collected. It's also important to add that during WWI, the Russian Army had attacked the country's Jews, calling them traitors (suspicions based in part on the fact that they spoke Yiddish, which sounded German, so they were assumed to be fans of the German enemy army). The army arrested Jews, and allowed their own soldiers to carry out some pogroms during WWI. This would have started the wave of antisemitism that only grew during the even greater tensions of the Civiil War. All of these factors give a general sense of the motivations behind the mass pogroms in the Russian Civil War. Ukraine also broke away and tried to form its own nation-state, and some of the people involved in that failed state project were particularly antisemitic, which I believe drove some specific pogroms in Ukraine. However, I'm not an expert on Ukrainian nationalism, so someone else might be able to offer more on that aspect. Sources: Oleg Budnitskii, Jews Between the Whites and the Reds; Jonathan Denkel-Chen (editor), Anti-Jewish Violence; Eric Lohr, Nationalizing the Russian Empire; Peter Gatrell, A Whole Empire Walking