Creating boundaries where there were none transformed the nature of food exchanges across many borders around the world. In Southeast Asia, South Asia, and East Asia, the trading of rice was among the traditional livelihoods affected by the transformation from untrammeled to regulated exchanges in grains, spices, and other food commodities. Rice was, and still is, the staple food of the people in these regions. It spelled food security and political stability rooted in traditional beliefs, rituals and cultural practices that are embedded in social networks and economic arrangements. With the emergence of the Philippine and Malaysian modern states after World War II, rules were subsequently imposed on the previously borderless maritime routes. Informal economic institutions, however, remain vibrant. This study examines the dynamics of rice smuggling through evidence from an in-depth case study of rice smuggling between Tawi-Tawi in the Philippines and Sabah in Malaysia, accompanied by mediated dialogues with smugglers and interviews of both legal and shadow authorities across the Sulu Sea. The study underscores how the desire for food security and political legitimacy, coupled with the salience of traditional and cultural ties and practices, and the taut social and economic networks inherited from the cross-border traders of the past, continue to lubricate rice smuggling in Southeast Asia.