Stalin initiated all key decisions during the Terror, personally directing many of its operations and taking an interest in their implementation. His motives in doing so have been much debated by historians. His personal writings from the period were — according to Khlevniuk — "unusually convoluted and incoherent", filled with claims about enemies encircling him. He was particularly concerned at the success that right-wing forces had in overthrowing the leftist Spanish government, fearing a domestic fifth column in the event of future war with Japan and Germany. The Great Terror ended when Yezhov was removed as the head of the NKVD, to be replaced by Lavrentiy Beria, a man totally devoted to Stalin. Yezhov was arrested in April 1939 and executed in 1940. The Terror damaged the Soviet Union's reputation abroad, particularly among sympathetic leftists. As it wound down, Stalin sought to deflect responsibility from himself, blaming its "excesses" and "violations of law" on Yezhov. According to historian James Harris, contemporary archival research shows that the motivation behind the purges was not Stalin attempting to establish his own personal dictatorship; evidence suggests he was committed to building the socialist state envisioned by Lenin. The real motivation for the terror, according to Harris, was an excessive fear of counterrevolution.