Western arms played a significant role as a new means of violence leading to the Meiji Restoration and in the ensuing civil war in Japan 1868–69. This chapter explores how industrial arms manufacturing and the global arms trade in the 1860s fueled wars in multiple locations worldwide including Japan. As domains and the Shogunate prepared for battle domestic demand for foreign arms soared precipitously overshadowing any other form of international trade. With their global and regional connections local Western merchants such as L. Kniffler & Co. in Nagasaki and the Schnell brothers in Yokohama supplied several sides in the Japanese conflict with military goods ranging in size from gunpowder to gunboats. Nevertheless, the rifle became the prevalent Western weapon for combat in Japan and it is the rifle that became the centerpiece of military strategy and social reform. Contrary to the prevalent image of arms trading limited to a few young risk takers like Thomas Glover, this study shows the widespread and short-term creation of military goods trade networks through abundant foreign supply and great domestic demand.