sentences:  In 1976, following the unification of Vietnam, some Spratly islands became a part of Khánh Hòa Province.To assert Vietnam's political sovereignty, the North Vietnamese military initially deployed four battalions of the 2nd Division from Military Region 5 to defend the islands.In September 1975 the North Vietnamese Ministry of Defense transferred the 46th Infantry Regiment from the PAVN 325th Division to the VPN, to form a brigade with the 126th Naval Regiment with the purpose of defending the Spratlys and other groups of islands.