A source of serious interstate tension between some members of the Association of Southeast Asian Nations (ASEAN) and China for much of the 1990s, territorial disputes in the South China Sea became less contentious in the early 2000s: A less assertive stance by China being a critical component in Beijing's Southeast Asian “smile diplomacy,” a diplomatic offensive designed to assuage the ASEAN countries' security concerns vis-à-vis a rising China. Recent controversies, however, have underscored the seemingly intractable nature of the dispute and the continued sensitivity over sovereignty issues, particularly between the main protagonists: Vietnam, China, and the Philippines. In the first part of a two-part series, this article examines the impact of the dispute on Vietnam's relations with the PRC.