was clearly understood by all the parties that the Republic of Vietnam inherit of all the French Indochina's Vietnamese territories under the 17th Parallel. As the Paracel and the Spratly archipelagos (which lay below the 17th parallel) were part of the French Indochina since 1933, they were part of "South Vietnam" territory. The French bestowed its titles, rights, and claims over the two island chains to the Republic of Vietnam. The Republic of Vietnam (RVN) exercised sovereignty over the islands, by placing border markers on the Spratlys to indicate South Vietnamese sovereignty over the archipelago. Up to the end of the Vietnam War the Republic of Vietnam Navy held military control over the majority of the Spratly Islands until 1975, when North Vietnamese troops attacked South Vietnamese troops and occupied the islands. After the Vietnam War, the unified Vietnam SRV (Socialist Republic of Vietnam) continued to claim the Spratly islands as an indisputably integral part of Vietnam. China has produced a letter written by North Vietnam's former Prime Minister Phạm Văn Đồng in 1958 as proof that it holds sovereignty over the Paracel and Spratly islands. The Vietnamese newspaper Thanh Niên News claims China has intentionally misrepresented the letter, which contains no direct reference to either island chain. In addition, they claim that China is ignoring the spirit and time in which the letter was written. During that time, the two communist neighbors shared extremely close ties and the US navy was patrolling the Taiwan Strait, threatening them both. The letter, according to the newspaper, represented a diplomatic gesture of goodwill that has no legal relevance to the current territorial dispute. On 4 September 1958, with the seventh fleet of the US Navy patrolling the Taiwan Strait, China announced its decision to extend the breadth of its territorial waters to 12 nautical miles. The United Nations (to which China was not yet a member) had just held its first Conference on the Law of the Sea in Switzerland in 1956, and the resulting treaties, including the Convention on the Territorial Sea and the Contiguous Zone, were signed in 1958. Though the UN conference was considered a success, it left the exact breadth of each nation's territorial waters somewhat unresolved; the US, for instance, said it should extend just three nautical miles. On 14 September 1958, North Vietnam's PM Phạm Văn Đồng wrote his letter to PM Zhou Enlai in response