Territorial disputes in the South China Sea in the context of "Gulf of Tonkin"

The South China Sea Islands consist of over 250 islands, atolls, cays, shoals, reefs, and seamounts in the South China Sea. The islands are mostly low and small and have few inhabitants. The islands and surrounding seas are subject to overlapping territorial claims by the countries bordering the South China Sea.

The South China Sea Islands constitute a distinct tropical moist broadleaf forest terrestrial ecoregion and the South China Sea Oceanic Islands marine ecoregion.

Maritime security is an umbrella term informed to classify issues in the maritime domain that are often related to national security, marine environment, economic development, and human security. This includes the world's oceans but also regional seas, territorial waters, rivers and ports, where seas act as a “stage for geopolitical power projection, interstate warfare or militarized disputes, as a source of specific threats such as piracy, or as a connector between states that enables various phenomena from colonialism to globalization”. The theoretical concept of maritime security has evolved from a narrow perspective of national naval power projection towards a buzzword that incorporates many interconnected sub-fields. The definition of the term maritime security varies and while no internationally agreed definition exists, the term has often been used to describe both existing, and new regional and international challenges to the maritime domain. The buzzword character enables international actors to discuss these new challenges without the need to define every potentially contested aspect of it. Maritime security is of increasing concern to the global shipping industry, where there are a wide range of security threats and challenges. Some of the practical issues clustered under the term of maritime security include crimes such as piracy, armed robbery at sea, trafficking of people and illicit goods, illegal fishing or marine pollution. War, warlike activity, maritime terrorism and interstate rivalry (such as the Territorial disputes in the South China Sea or conflict in the Strait of Hormuz) are also maritime security concerns.

While a concern throughout history for nation states, maritime security has evolved significantly since the early 2000s, when in particular concerns over terrorist attacks on port facilities sparked interest in security in the maritime domain and led to the creation of the International Ship and Port Facility Security Code. The ISPS Code is enforced through Chapter XI-2 of the SOLAS Convention. Most littoral states and international organisations have also outlined maritime security strategies. It is in particular piracy in Southeast Asia, off the coast of Somalia and in West Africa which has triggered recognition for the detrimental effects of maritime insecurities for economic development, human security as well as the environment. Maritime security is often transnational and goes beyond the maritime domain itself (see liminality). It is characterized as being cross-jurisdictional and/or highly jurisdictional complex.