His own SS colleagues considered him brutal, and an SS judge at his Greek trial described him as a drunkard "primitive in all his thoughts and feelings" — a rare candor that underscores just how far outside accepted norms his conduct fell even within a system defined by organized violence. As commandant of two concentration camps, first at Syrets in occupied Ukraine and then at Haidari near Athens, he imposed regimes of deliberate cruelty: punishment for minor infractions, labor designed not for productivity but to destroy morale, and personal acts of lethal violence carried out before assembled prisoners. Eyewitness testimony from Haidari places the number executed during his tenure in the hundreds, with thousands more processed through the camp's systematic brutality. His career ended not through Allied justice but through a drunken altercation with his own adjutant, which led to his demotion and removal — a measure of how thoroughly he had made himself ungovernable even to his superiors.

His case sits at an unusual intersection of white-collar crime and homicide — a skilled forger and check fraudster whose financial schemes gave him the tools to obscure his killings, making victims appear alive through fabricated records long after their deaths. The FBI's use of him as a paid informant during the period he was actively murdering raises unresolved questions about institutional oversight and the costs of that arrangement. Investigators have linked him to as many as twenty-five deaths in total, though only four convictions were secured.

His reign began with a constitution and ended with its suspension — a pattern that defined the decades that followed. Ruling as an autocrat for thirty years, Abdul Hamid II presided over the systematic massacre of Armenians and Assyrians in the 1890s, events that drew international condemnation and prefigured the catastrophes of the following century. His use of pan-Islamic ideology and a vast network of spies and informants allowed him to maintain control over a weakening empire even as its territorial losses mounted.

As Japan's Foreign Minister across three separate terms, Arita shaped the ideological language through which Imperial Japan justified its military expansion across Asia and the Pacific. The phrase he coined — Greater East Asia Co-Prosperity Sphere — gave a veneer of regional solidarity and anti-colonialism to a project of conquest, functioning as some of the most consequential political framing of the twentieth century.