A Russian-language specialist, he was assigned to the staff of General Gregorii Semenov, a vehement anti-Semite who distributed copies of the Protocols of the Elders of Zion to all of his troops, along with weapons and rations.

Along with a few dozen other Japanese soldiers, Yasue read and accepted the premises of the Protocols, and would allow this to guide much of his actions and views into the time of the beginning of World War II.

After his return to Japan in 1922, Yasue worked in the Army Intelligence Bureau, translating the Protocols of the Elders of Zion into Japanese, while continuing to speak with Inuzuka and a handful of others about the Jewish problem in Russia.

There, he traveled much of the country, and spoke to a variety of people, including noted Jewish leaders such as Chaim Weizmann and David Ben-Gurion, farmers, shopkeepers, and rabbis.

As war approached in the 1930s, Yasue's influence, and that of his comrades, deepened, particularly among those who were distraught by the lack of respect Japan received on the world stage, and who were wary of the cultural changes that accompanied "progress."

It was at this time that Yasue and his "Jewish experts" met the so-called "Manchurian faction," a number of industrialists and military officers who saw Manchuria as crucial to Japan's success.

The plan hit a major obstacle almost immediately after it was conceived; two years after the Mukden Incident which spurred the Japanese invasion of Manchuria, a young Jewish man named Simon Kaspe was kidnapped, tortured, and murdered.

Yasue, now promoted to colonel, was assigned to the city of Dairen (now called Dalian), but continued to commute to Harbin to speak with Kaufman and for other meetings and activities related to his plans regarding the Jewish communities.

Though he remained a representative for the government, and continued to be active to a degree in the execution of the Fugu Plan, he could not formally retain his post as an overt member of a pro-Jewish faction.

Though he had contributed for a time to various publications on the Jewish situation, including Kokusai Himitsu Ryoku no Kenkyu (国際秘密力の研究, Studies in the International Secret Power), under the pen-name Hokoshi, he ceased participating in such things upon his dismissal.