This paper attempts to examine the dynamic of Vietnam’s foreign policy toward the United States and China since the early 1990s. It gives an insight in Vietnam’s balance-of-interests strategy with the two powers in economic, political and security perspectives and explores why and how Vietnam’s navigation of its relations with the two powers has undergone significant changes. The paper argues that in the 1990s, Vietnam’s diplomatic energies were focused on developing relations with China over the United States given China’s geographical contiguity and the salience of aggravating territorial disputes, and the ideological solidarity in part to hedge against risk posed by the United States. This situation, however, began to change in the early twenty-first century as Vietnam sought to realize the full potential of economic partnership with the United States for its international economic integration and as China presented its unprecedented increasing assertiveness in the South China Sea, which, taken together, has intruded into Vietnam’s rapprochement with the United States. However, the prospect for a close strategic partnership or a soft alliance between the two countries seems unlikely for the foreseeable future as in any case a close military relationship between Vietnam and the United States would greatly antagonize Beijing. How could Hanoi manage its relations with the two great powers to remain safe and beneficial in the middle path remains an issue of particular concern, accordingly.