How Vietnam Can Balance Against China, on Land and at Sea

Vietnam hosted its first international defense expo in mid-December, in a move to diversify its weapons suppliers away from Russia. In addition to the technical aspect of weapons, the expo was also an opportunity for partners such as the United States or India to foster a closer defense relationship with Hanoi, and to signal to China that Vietnam is serious about modernizing and diversifying its armed forces.

Where does this expo fit into Vietnam’s general security strategy? While the country prioritizes maintaining good relations with China to avoid unnecessary conflicts, it is looking for options that can help minimize the negative impact of aggressive Chinese behaviors in the short term and to prepare for the worst in the long term. Vietnam will balance against China once deferring to it does more harm than good. The expo without a doubt fits the country’s “Three Nos” non-aligned foreign policy, for it does not commit Hanoi to other powers but assists its arms production and modernization. 

But the key question remains: How can Vietnam balance against China?

A country has two main ways to balance against a threat: internal balancing via domestic arms production and external balancing via military alliances. Vietnam’s non-aligned foreign policy means that it has picked the first option while reserving the second option for the future. But while it is tempting to suggest that Hanoi picked the first option due to its own agency, ignoring the geographical source of that decision is detrimental to understanding the systemic factors that have driven Vietnam’s grand strategy since the country’s founding in 1945. Vietnam’s geography is deeply hostile to it nurturing an alliance relationship with any external great power other than China, and it is geography that has pushed Vietnam to adopt the option of internal balancing.

Vietnam borders a strong China to the north, a mountainous Laos to the west, a suspicious Cambodia to the south, and a disputed sea to the east. The country has therefore long lacked strategic depth or a distance from Vietnam’s frontline to its heartland. General Vo Nguyen Giap noted that on the eve of the First Indochina War:

“Indochina is a strategic unit, a single theater of operations. Therefore we have the task of helping to liberate all of Indochina… especially for reasons of strategic geography [emphasis added], we cannot conceive of a Vietnam completely independent while Cambodia and Laos are ruled by imperialism.”

This lack of strategic depth means that Hanoi will have little warning in the event of a massive invasion, and will always have to rely on itself first and foremost because an external helper will not be able to respond quickly enough.

A case in point is the Chinese invasion of Vietnam in 1979. The China-Vietnam border at Friendship Pass is less than 180 kilometers away from Hanoi and it took China roughly two weeks to capture Lang Son and advance more than 50 kilometers into Vietnamese territory. From Lang Son, 120 kilometers away from Hanoi, China could have launched a direct assault on Vietnam’s capital, but it decided to withdraw after successfully teaching Vietnam a short but costly “lesson,” in order to avoid Soviet intervention. Because of their great distance from Vietnam, the Soviets could do little to help it quickly and directly under the terms of the Soviet Union-Vietnam Treaty of Friendship and Cooperation, apart from an airlift of arms and a naval deployment off the coast of Vietnam. Vietnam’s battle-hardened military was thus vital to slowing down the Chinese advance. Had Vietnam relied exclusively on the Soviet Union and neglected its own army, it would have been defenseless against China.

Even when there was an external power stationed on Vietnamese soil, China was committed to driving that power off Indochina. Beijing assisted the Viet Minh and later North Vietnam to successfully defeat France and the United States and their client states in 1954 and 1975, respectively. China’s geographical closeness to Vietnam means that it can always pour more resources into Indochina than any other great power can, and it has the resolve to challenge those powers’ presence on its periphery at all costs. 

Vietnam was always under the Chinese sphere of influence before the decline of the Qing Empire weakened China’s ability to respond to French colonization of Vietnam. Now that China is strong, no external great powers can come to Vietnam’s continental defense even if they are committed to doing so. The recent failures of the French, the Americans, and the Soviets to establish and maintain a military outpost in Indochina is a constant reminder of Chinese determination to use force against external powers on its periphery, and Vietnam’s inability to rely on external balancing on land.

Moreover, different from Ukraine’s location bordering the North Atlantic Treaty Organization, which allows it to receive steady flows of arms from the West, Vietnam borders no other great powers’ sphere of influence. That geographical isolation means Vietnam will have to rely on its own arms inventory if a war with China breaks out. Hanoi’s emphasis on modernizing its defense industry and its eschewing of foreign alliances strongly reflects the limited options imposed by geographical proximity to China.

But Vietnam cannot compete with China in terms of resources, and it faces another hard choice when it comes to internal balancing as well: whether to modernize its navy and air force or invest more in the army in order to slow down weapons obsolescence. Vietnam’s army is no match for China’s army, and it cannot rely on an external security guarantor due to hostile geography. As such, Vietnam needs to prioritize its army over the navy and air force to ensure that China cannot exploit its lack of strategic depth.

An orientation of resources away from the maritime domain, however, does not equate to an orientation of attention. Vietnam should not abandon its claims in the South China Sea just because it must prioritize continental defense. While Vietnam cannot rely on an external power for continental defense, it can luckily do so for maritime defense. 

East Asia is divided into two distinct spheres of influence with China dominating continental Asia and the United States controlling maritime Asia. In contrast to the geographical exclusivity of Vietnam’s continental landscape, its maritime geography is open to all external powers. This allows Vietnam to internationalize the South China Sea disputes, a move that China does not like, and fosters closer defense relations with other great powers via port visits. Importantly, those port visits cannot fundamentally threaten China’s exclusive continental sphere and thus are less provocative than a permanent foreign military base on Vietnamese soil, one of Vietnam’s Three Nos.

The inclusive nature of the South China Sea opens the possibility of Vietnam shifting the burden of balancing China in the maritime sphere onto the great powers with vested interests in a free and open Indo-Pacific, while saving resources for internal balancing on land. And this move also fits with Washington’s distaste for fighting a land war in Asia against China. The United States has embraced this formula, as seen in its transfers of naval assets to Vietnam and its involvement in challenging Chinese maritime claims. Vietnam and the United States, as well as other members of the Quadrilateral Security Dialogue, commonly called the Quad, should continue strengthening cooperation over maritime security to help Hanoi address its resources scarcity in modernizing its armed forces and devote more money to continental defense. Internal balancing on land and external balancing on sea should be the two key tenets of Vietnam’s security policy.

There is a Vietnamese saying, “Nuoc xa khong cuu duoc lua gan” – “Distant water cannot put out a nearby fire” – which emphasizes Vietnam’s preference to always rely on itself to balance against China rather than another distant great power. Vietnam’s lack of strategic depth and its proximity to China limit its and other great powers’ options for protecting Vietnam. The defense expo was another forum for Vietnam to address the growing imbalance of power with China under its self-reliant security policy, and we should expect Vietnam to continue the process of arms diversification given that Russia can no longer serve as a reliable supplier. History has shown that Vietnam can only be secured when its army is strong, and its weapons are abundant.