In 1922, Mashbir completed a dangerous mission in Vladivostok, Russia, preventing the outbreak of a regional war between Japan, China, and Russia, which might have expanded further!
The following year on September 1, 1923, the most destructive natural disaster in modern Japanese history occurred, The Great Kantō Earthquake (関東大震災, Kantō daishinsai), a Japanese natural disaster in the Kantō region of the island of Honshū. This earthquake destroyed Tokyo, the port city of Yokohama, surrounding prefectures of Chiba, Kanagawa, and Shizuoka, and approximately 140,000 people died. During the challenging first months following that major disaster, Mashbir spearheaded an American Medical Relief Effort to assist many of the injured Japanese – As part of this humanitarian process, Mashbir created the first English – Japanese Medical Translation Dictionary that was used by English speaking health care workers while treating Japanese speaking patients.