The root of this interdependence was coal: Britain’s carbon empire and France’s lack of it. French coaling stations in the above-mentioned British ports and the sourcing of these coal supplies (usually from Britain and Australia) were vital to the coal-fueled shipping routes, packet services, naval vessels, and troop transports which traveled between metropolitan France and Indochina. By the end of the nineteenth century, coal was increasingly important for use within Indochina as well (on Doumer’s trains and in Saigon’s rice processing plants). As French Indochina grew, it thus grew more carbon- and communications-interdependent with British sea ports. Indeed, even as French authorities secured access to known coal supplies in Tongking after 1885, Indochina remained enmeshed in an international carbon economy which drew French coal to British Hong Kong—redefining, but not severing carbon interdependence. This chapter makes use of naval, colonial and diplomatic archival sources from France, Britain, Vietnam, Singapore, Sri Lanka, and Hong Kong.