"In these years of the Popular Front, the Soviet killings and deportations went unnoticed in Europe. Insofar as the Great Terror was noticed at all, it was seen only as a matter of show trials and party and army purges. But these events, noticed by specialists and journalists at the time, were not the essence of the Great Terror. The kulak operations and the national operations were the essence of the Great Terror. Of the 681,692 executions carried out for political crimes in 1937 and 1938, the kulak and national orders accounted for 625,483. The kulak and the national operations brought about more than nine tenths of the death sentences and three quarters of the Gulag sentences."
Timothy Snyder, Bloodlands: Europe between Hitler and Stalin (New York: Basic Books, 2010), 107.