白龍尾島是什麼

白龍尾島是中國和越南之間的爭議海域北部灣上的一個小島。

主权争议
一些中国人士主张的看法认为，在越南抗法战争期間，中華人民共和國把這個小島借給越南用作海军基地。之後兩国于1957年簽訂协议，中国将白龙尾岛转交越南。并暂时搬迁了岛上原住中国人，这也是越南现在要求此地的借口之一。
1887年（清光绪十三年），清朝与法国签订边界条约，划分中国与法属印度支那边界。以商务利益换得钦州的江坪、黄竹两处越南飞地。对于海上边界的划分，法国提出以北仑河河口所在的东经108度03分向南延伸，作为海上岛屿及北部湾的划分界线。根据这一划法，白龙尾岛将归法国所有。但这一分界方法没有被中国接受，在中华民国时期的中国及外国地图上（Goode's World Atlas, Rand McNally, 1933)，白龙尾岛仍在中国一侧。多数国外学者亦认为白龙尾岛直至1950年代仍然是中国领土（参见引文）
The core issue to be settled in the Gulf of Tonkin is which principle should be used in order to divide the Gulf. In this context, the impact of islands is of crucial importance and, in particular, the Vietnamese controlled Bach Long Vi Island. The first question is whether or not it qualifies as an island according to the provisions of the 1982 United Nations Law of the Sea Convention (1982 UNCLOS). If it does impact on the tracing of a line of equidistance if this principle is applied in the Gulf of Tonkin. Logically, Vietnam would take the position that Bach Long Vi Island should have its full impact in any agreement on how to divide the Gulf. On the other hand, China has an interest in minimising the impact that the Island would have on any agreed delimitation. This could be done by, either arguing that Bach Long Vi is not an island in accordane with the provisions of 1982 UNCLOS or, by arguing that its impact should be minimised and possibly even be disregarded. For China to argue that it is not an island would be counterproductive as China has earlier controlled the island and has claimed that the island was inhabited before it was handed-over to Vietnam in the late 1950s. (The Management of the Border Disputes Between China and Vietnam and its Regional Implications by Assoc.Prof.Ramses Amer, Co-ordinator, South-East Asia Program (SEAP), Department of Peace and Conflict Research, Uppsala University, and Senior Research Adviser, Department of Research Co-operation-SAREC, Swedish International Development Co-operation Agency (SIDA), October 2000)
根据中国外交部条约法律司海洋处处长萧建国2004年8月3日的声明，北部湾划界不涉及白龙尾岛主权。该处官员以及中国边疆史地研究中心、中国国家海洋局的官员随后又明确指出“白龙尾岛确实处于越南的实际管辖之下。”