Original sentence: He was directly or indirectly responsible, certain historians allege, via his policies, for tens of millions of deaths and unjust deportations to labour camps in the Soviet Union.Stalin's cult of personality, his extreme concentration of power and the means of its execution have led some to define him as a dictator
Edited sentence: He was directly or indirectly responsible, via his policies, for tens of millions of deaths and unjust deportations to labour camps in the Soviet Union.Stalin's cult of personality, his extreme concentration of power and the means of its execution defines him as a dictator