The article presents the results of a study on the influence of the Eurasian System of Arcs of Instability on territorial disputes in the South China Sea (SCS), the priorities of the United States, People’s Republic of China, Vietnam and the Russian Federation regarding the SCS in accordance with the strategic levels of Sun Tzu, as well as the impact of these factors on the development of internal political situation in Vietnam. The current rapprochement between Hanoi and Washington can be viewed as a logical result of Chinese policy in the SCS. The current policy of Beijing is counterproductive, because it pushes Vietnam into the sphere of dominant US influence, which in the long range is unfavorable for the PRC. The possible transition of Vietnam to the other side of the East Asian segment of the Eurasian Arc of Instability will become the most important geopolitical defeat of the PRC since its foundation in 1949. Growing tensions in US-China relations and in Vietnamese-Chinese relations create favorable conditions for strengthening Vietnamese-American relations, but the reinforcement of ties with the United States creates specific threats to homeland political stability in Vietnam. In this situation, the scenario of relying on the United States to protect the faraway borders (islands) from China’s expansion in SCS is risky for Hanoi, because following the stratagem “Befriend a distant state and strike a neighbouring one” poses a threat to the stability of regime in Hanoi. To sum up, the current foreign policy situation is not very favorable for the protection of Vietnam’s interests in the SCS, relying on the United States. The problem is aggravated by the remarkably reduced level of propaganda of Hanoi, both in the country and abroad, which is used by external forces to support opposition to the regime.