G2 was headed by the irascible and vehemently anti‐communist Major General Charles A. Willoughby (1892–1972). Willoughby, who was the son of a German father and American mother and whose birth name was Adolf Tscheppe‐Weidenbach, had moved to America at the age of eighteen and become a naturalized U.S. citizen.

As Takemae Eiji notes, “fellow Occupationaires mocked the General’s stiff Prussian bearing, referring to him alternately as ‘Sir Charles’ and ‘Baron von Willoughby’… Regarded as a martinet by his subordinates — he took a perverse pride in the epithet ‘Little Hitler’, and even MacArthur dubbed him ‘my loveable fascist’ — the volatile Willoughby nonetheless enjoyed the Supreme Commander’s full confidence”.

[…]

Eventually, it was the CIA that gained the upper hand in the struggle for intelligence control. Immediately after MacArthur’s dismissal in April 1951, Willoughby too returned to the United States in a state of “nervous slump”, handing over to the CIA his files, many of his contacts in Japan, and his messages of concern about the need to continue protecting and nurturing the former senior Imperial Army officers whom he considered “essential for rearmament”.

[…]

Arisue’s new position of trust with the American forces enabled him to provide financial support to Kawabe Torashirō, who also soon became a key informant to the occupation forces; and Arisue then proceeded to recruit a number of other leading former military figures, including Hattori Takushirō, who had held key positions in the Imperial army general staff, and later Tsuji Masanobu, a wartime colonel and military strategist who was regarded as one of the architects of the invasion of Malaya and Singapore, and had gone into hiding during the early occupation era after being listed as a Class A war criminal.

As Willoughby later wrote, these people had been “the brains” of the former Imperial Japanese general staff: “monographs were just a cover, to keep them from starving”. Equally importantly, the research activities of Arisue, Kawabe, Hattori, Tsuji and others enabled them to become crucial conduits of information for the U.S. occupiers — a rôle to which they took with enthusiasm.

They rapidly reestablished their authority over now unemployed former military subordinates, creating a web of private intelligence organizations which provided information to the Americans in return for a variety of monetary and other rewards. This web, as we shall see, extended across borders into many parts of the former Japanese empire.

(Emphasis added.)