This article foregrounds a case of informal diplomacy with far reaching consequences for the international politics of postcolonial Indonesia and capitalist Southeast Asia during the Cold War. The case is Suhartoâ€™s New Order Indonesia (1966â€“ 1998), where the Republicâ€™s diplomacy was dominated not by the foreign ministry but by a small elite network (jaringan) of sectarian activists of Catholic faith allied with military officers of an intelligence background against Communism and Islam. Operating under the patronage of intelligence czar Ali Murtopo, this jaringan emerged as a powerful and conservative channel of influence on the early New Order and steered some of its major diplomatic initiatives: from the covert diplomacy that ended Konfrontasi, and the founding and elaboration of ASEANâ€™s diplomacy, to planning and justifying the annexation of East Timor in 1975. The article moves in three steps. One, it situates the New Orderâ€™s informal diplomats in the long arc of diplomacy in postcolonial Indonesia. Two, it atomizes this network in sociological terms and probes how the habitus of its members shaped the substance and style of their diplomatic practices. Three, it examines the main foreign policy initiatives of this network. This Indonesian case brings to the study of informal diplomacy an appreciation of how partisan networks embedded in domestic and international circuits â€“ rather than standalone individuals â€“ shore up a strongman. It also offers insight into the tortured fightback by actors of â€˜formalâ€™ diplomacy as they come under the assault of informal diplomats and their patrons.