Recently the NHK News reported the following:
It was expected that Vietnam would be announcing that a rescue training would shortly be held jointly with American naval forces, and this could bee seen as aiming at restraining China that had conflicts over the sovereignty such as Spratly Islands in the South China Sea.
At a regular press conference held on the 23rd, spokesperson Gwen Fung Gurr of the Vietnamese Ministry of Foreign Affairs said that warships of American naval forces would make a port call to Vietnam, and to hold joint training on salvage operation; on top of that it was clarified that "the relation between the naval forces of the two countries would become strengthened", and emphasized the meaning of the operation. It was expected that training would be held for several days in the offing in Danang in Vietnam's central part during the latter half of next month. Naval forces of the two countries did similar training last August, and this time become a continuous exchange in two consecutive years. Between Vietnam and China there were continuing disputes over the sovereignty patrolling right over the Spratly Islands etc. in the South China Sea; since last month events such as that the fishing boat of Vietnam was being threaten by shooting, and the exploring activity of the national oil company ship was obstructed by China continued one after another. Such a situation was noted, and earlier US's Secretary of Defense Gates said "The presence of the U.S. Army in South East Asia etc was strengthened", and the up coming policy was to increase US Army activities in this region. This two-country combined training of Vietnam and the American was expected to aim at restraining China that was increasing its influence in the South China Sea.
In view of the South China Sea disputes, it is natural for Vietnam to form a closer relationship with the US.