Vietnam is a coastal state and a disputing party in the South China Sea (SCS), which is called the East Sea in Vietnam due to its location vis-à-vis its mainland. Within the framework of this chapter, these two terms are used interchangeably. There, Vietnam claims sovereignty over the land features in the Paracels and Spratlys, and over a suite of maritime zones as stipulated by the United Nations Convention on the Law of the Sea (UNCLOS), which overlap wholly and partly with those of its neighbours. The country has been well-known as one of the claimants which has stood firmly in a series of stand-offs with its giant neighbour, China. It is a big puzzle for many why Hanoi would risk antagonizing Beijing, its most important neighbour, for a bunch of remote, barren and tiny features in the middle of the sea and for the waters off its coast. This chapter builds on the existing literature of Vietnam's maritime activities and its statecraft to map and identify the importance of the East Sea in the Vietnamese perspective throughout the course of history. It should be noted that the SCS and the offshore islets have not only been incorporated into Vietnam's political geography since at least the 17th century but also into its strategic thinking. In other words, the sea and islands serve as a layer of defence that increases the country's strategic depth.

Lack of strategic depth and insecurity

Vietnam's strategic thinking is conditioned by history and geography. The combination of the asymmetry of power and geographical proximity created a permanent concern among Vietnamese political elites about the Northern threat. History textbooks remind schoolchildren about the bitter experience of King An Du’o’ng Vu’o’ng in trusting Chinese General Zhao Tuo (magistrate of Nanhai Province), which resulted in the fall of the Âu Lạc Dynasty in 179BCE and a longue durée of Chinese suzerainty. Consequently, such a dark time under the Chinese yoke, or “a millennium of grievance,” created a deep sense of insecurity and served as an undying reminder of the danger from the North.

Geographically speaking, Vietnam's most dominant feature is the lack of strategic depth. The concept broadly refers to the distance between the frontline and the country's core areas, including the capital and main industrial cities.