Tensions between China and the Philippines have escalated dramatically in recent months around Second Thomas Shoal, a submerged reef in the eastern Spratly Islands. The Chinese Coast Guard has repeatedly attempted to block delivery of food, water, and building supplies to the Philippine marine detachment aboard the BRP Sierra Madre, a World War II–era warship grounded on the shoal since 1999. In at least two incidents since March, China’s use of coercion has injured Philippines sailors. The risks of escalation are serious. The United States has said its defense obligations under the Mutual Defense Treaty extend “to armed attacks on Philippine armed forces, public vessels, or aircraft — including those of its Coast Guard — anywhere in the South China Sea.”
But while China has been escalating with the Philippines at unprecedented levels around Second Thomas Shoal, it has exercised striking restraint toward Vietnam’s far larger and more militarized expansion of its South China Sea outposts. There is no record of China using paramilitary or military forces to disrupt Vietnam’s land reclamation in the Spratly Islands. As Zack Cooper and Greg Poling have recently noted, China’s assertiveness toward the Philippines and restraint toward Vietnam is especially puzzling given that the former is a U.S. treaty ally while the latter is not. Alliances with great powers are supposed to deter aggression, not to invite it. This is a puzzle that warrants scrutiny not just to help illuminate the nature of Chinese strategy in one of the world’s leading flashpoints. Deciphering the logic behind China’s conduct also has direct implications for how the United States and its allies can best defend their interests in the South China Sea and beyond.
There are a number of potential explanations for China’s behavior. Below I describe five possibilities, each of which is derived from a more general explanation of China’s conduct in the South China Sea. Although several capture important elements of Chinese strategy, none are able to satisfyingly explain the variation in Beijing’s conduct highlighted above. So, I offer an alternative explanation, one rooted in how Chinese leaders conceptualize the South China Sea disputes and the dilemmas they present. Beijing’s conduct toward the Philippines and Vietnam differs because Manila and Hanoi have different capacities to impose strategic costs on Beijing. Relative to the Philippines, Vietnam has a greater ability to impose such costs on China. Paradoxically, Manila’s alliance with Washington circumscribes its capacity to impose such costs, while Vietnam’s nonaligned status increases its ability to do so.
Five Possibilities
The first explanation focuses on China’s interest in preventing its rivals from taking collective action against it. This so-called “divide and rule” strategy holds that Beijing uses combinations of carrots and sticks to drive wedges between its rival claimants to doom any prospect for collective action among them. From such a perspective, Chinese restraint toward Vietnam could be a function of its ongoing standoff with Manila at Second Thomas Shoal and meant to avoid creating another crisis with another rival at the same time.
While Beijing certainly has an interest in preventing or forestalling the emergence of collective resistance among its rivals, this is an unsatisfying explanation. Chinese coercion around the BRP Sierra Madre began over 10 years ago, and since then it has regularly escalated concurrently with Vietnam (and its other South China Sea rivals). More to the point, even if concern about pushing Manila and Hanoi into a united front contributed to Beijing’s restraint toward the latter, this explanation is unable to tell us why Beijing elected to continue to contest Philippine consolidation instead of challenging Vietnamese land reclamation while exercising restraint toward Manila — a policy combination with presumably the same effect.
The second explanation focuses on China’s interest in remaining in the “gray zone” and avoiding war in the South China Sea. Beijing, of course, has gone to lengths to advance its South China Sea claims while avoiding armed conflict. From this perspective, variation in Beijing’s responses to Philippine and Vietnamese consolidation could be explained with reference to their respective propensity for escalation. While Vietnam has a demonstrated history of resisting Chinese predations, Manila does not. Chinese analysts attribute Manila’s restraint in large part to Washington’s unwillingness to allow its ally to run risks of the kind likely to trigger its mutual defense commitments. The United States, Chinese analysts argue, seeks to “intervene but not become entrapped” in the South China Sea disputes.
While this explanation, too, captures an important element of Chinese strategy, it obfuscates deeper drivers of it. Most obviously, it begs the follow-on questions: Why is Beijing so keen to stay in the gray zone, and why would it be so concerned with the possibility of Vietnamese escalation? China has used military force in the South China Sea before, including in the post-Mao era, and it did so by targeting Hanoi. In a conflict today, China would quickly dispatch with Vietnamese resistance, as it did in 1974 in the Paracels and in 1988 in the western Spratly Islands. As argued below, it is not the risk of escalation itself — or even the possibility of war with Hanoi — that has produced restraint in Beijing. Rather, it is the potential second-order consequences of such a conflict.
A third explanation focuses on the close political relationship between China and Vietnam. Although distrustful of each other, both states are run by communist parties that have much in common. They are united in their collective resolve to preserve their party’s monopoly on political power and both are acutely threatened by Washington’s promotion of democracy and human rights. They are also determined not to allow their bilateral relationship to deteriorate as it did in the late 1970s, and they have built an unparalleled network of government and party ties to help buttress it. From this perspective, Chinese restraint toward Vietnam’s land reclamation may reflect its interests in maintaining healthy ties with Hanoi. Beijing may be particularly inclined to soft peddle the disputes now, as the country’s conservative new president seems likely to be especially deferential to Beijing.
While China’s relationship with Hanoi is unique among its South China Sea rivals, close political bonds between the two can — and often have — cut the other way. Confident that its political ties with Hanoi will enable it to manage escalation and avoid incurring major costs, China has regularly escalated with Vietnam in the South China Sea and done so increasingly over the last 20 years. This explanation sheds little light on why Beijing has exercised such restraint when confronted with the large-scale expansion and fortification of Vietnam’s South China Sea outposts.
A fourth explanation centers around China’s perception of threat associated with the U.S.–Philippine alliance. Since the late-1990s, Chinese leaders have believed that the United States is using its alliances as anchors of an anti-China coalition aiming to thwart Beijing’s rise. This view, of course, has grown in recent years. Chinese analysts and state-controlled media regularly suggest that Washington uses the Philippines’ and Japan’s offshore disputes with China to advance its hostile strategic intentions toward Beijing. From this perspective, Manila’s alliance with Washington may make its conduct in the South China Sea more threatening for Beijing than that of nonaligned Vietnam.
To be sure, Chinese leaders perceive this alliance to be threatening. This cannot, however, explain China’s variable approach to Philippine and Vietnamese efforts to consolidate their South China Sea occupations. Most basically, it stretches credulity to suggest that the Philippine presence on a decaying ship is especially threatening. However, even accepting the premise that China’s conduct is driven by fear of the U.S.–Philippine alliance, Beijing would not focus its coercive efforts on the most vulnerable of Manila’s outposts. It would focus instead of one of Manila’s eight larger occupations, some of which have been expanded in recent years and all of which would have greater military utility. Furthermore, to whatever degree Washington benefits from the South China Sea disputes, it seems clear that the Philippine presence on Second Thomas Shoal is on balance a liability — not an asset — for it. As Chinese analysts correctly note, the United States does not want to be dragged into an armed conflict in the South China Sea, and especially not one over a submerged reef that does not even have the legal status of a rock.
A fifth, and related, potential explanation also centers around the U.S.–Philippine alliance but for different reasons. Because Beijing views the alliance in threatening terms, some analysts suggest that Beijing coerces Manila in the South China Sea to drive a wedge into the U.S.–Philippine relationship. Chinese pressure around Second Thomas Shoal, the thinking goes, will expose and exacerbate cleavages between Washington and Manila, undermining the alliance. China scholar Robert Ross has recently put forward just such an argument, suggesting that Beijing targets Manila not simply because it is a more menacing rival but because it is a more enticing target. Vietnam’s lack of an alliance with the United States, on the other hand, means that coercing it carries less strategic upside.
This argument is intuitively appealing but there does not seem to be any evidence supporting it. Of course Beijing would be pleased to weaken the U.S.–Philippine alliance, but its conduct in the South China Sea is not designed to do so. Over the last 30 years, Beijing has watched as its assertiveness toward the Philippines has time and again strengthened — not weakened — the alliance. Even when it had opportunities to weaken the alliance, as it did under the administration of Rodrigo Duterte, its coercive conduct in the South China Sea ensured that it would be unable to do so. If it were interested in using the disputes to undermine the alliance, it would have changed course.
As noted below, the existence of the U.S.–Philippine alliance — and the lack of an American alliance with Vietnam — are key factors shaping China’s approach to each. This has nothing to do, however, with Beijing viewing Philippine behavior as especially threatening or with it pursing a wedging campaign. Rather, the existence of the U.S.–Philippine alliance has counter-intuitively circumscribed Manila’s capacity to impose strategic costs on Beijing. This is a limitation that Vietnam does not have.