Some Vietnamese military officers are also attending staff training courses in Japan. In keeping with the nation's new defence stance, Vietnam is building up its air and sea forces. Concern over Beijing's ambitions Vietnam has long had a ambivalent relationship based on rivalry with its former colonial ruler, China. The most potent assets in the current SRVN order of battle are four Russian-built Tarantul missile corvettes, and the first of two indigenous corvettes is currently undergoing trials. The SRVN's first submarines, a pair of Sang O boats purchased from North Korea, are now in service.
Intelligence reports indicate that they are active in sea areas near the Sino-Vietnamese border.
Vietnam is giving great priority to protecting national interests in the strategically vital Spratly Islands in the South China Sea. A sea battle in 1988 resulted in Beijing wresting control of a number of these islands from Hanoi. Vietnam is fearful of a repeat move from China, and the last two years have seen the Vietnamese boost their military presence in the disputed island group. Hanoi's troops now occupy at least 25 islets in the group, and the Vietnamese media has stepped up its coverage of the Spratlys. Also, SRVN patrolling of the sea approaches to the Spratly Islands is intensifying, a trend that seems certain to continue.