Ahead of its much-anticipated chairmanship of the Association of Southeast Asian Nations (ASEAN) next year, and amid a months-long naval showdown in the South China Sea, Vietnam has hinted at the possibility of legal warfare against China. Vietnamese deputy foreign minister Le Hoai Trung openly warned in early November that diplomacy isn’t the only tool at Hanoi’s disposal. Emphasizing the need for exploring alternative strategies, he cited “fact-finding, mediation, conciliation, negotiation, arbitration, and litigation measures” as potential countermeasures against China’s maritime assertiveness.

Based on the Philippines’ experience in its arbitration case against China, lawfare seems a risky yet potentially viable option for Vietnam. Beijing proved willing to employ numerous economic levers to punish Manila for filing that case in 2013; Vietnam, which is much more dependent on trade with China, could face significantly greater economic damage if it filed a case. But the payoff could be worth the risk.

The 2016 arbitral award in the Philippines’ case proved the viability of compulsory arbitration under the United Nations Convention on the Law of the Sea (UNCLOS) and censured China’s excessive anachronistic claims and maritime aggression. Lawfare, and the threat of its use, provides unique leverage for smaller states confronting a desperate asymmetry of power vis-à-vis China.

In recent months, top Vietnamese officials and experts have repeatedly underscored the centrality of UNCLOS in resolving South China Sea disputes. Deputy Foreign Minister Trung emphasized that “the UN Charter and UNCLOS have sufficient mechanisms for us to apply those [legal] measures.” An influential Vietnamese think tank held a high-profile public forum in October where leading experts advocated filing an arbitration case against China to “identify who is right and who is wrong in this matter.”

China, however, has characteristically shot back, warning Vietnam against “complicating” the dispute. Geng Shuang, a spokesperson for China’s Ministry of Foreign Affairs, cautioned Vietnam against “actions that may complicate matters or undermine peace and stability in the South China Sea as well as our bilateral relations.”

China reason to worry. In 2013, the Philippines, despite the misgivings of many of its own lawyers and officials, sought the creation of a special tribunal under the compulsory dispute settlement mechanisms of UNCLOS to arbitrate some of its disputes with China. Beijing responded with a boycotts and other economic pressure, systematic smearing of the tribunal, and diplomatic intimidation to forestall a legal setback.

But the tribunal rejected Beijing’s arguments that it was exempt from compulsory arbitration. In its final award, the court not only invalidated China’s nine-dash line claim, but also censured Beijing for its harassment of Filipino fishers and ecologically disastrous island building activities in disputed areas.

By ruling that none of the Spratly Islands legally qualify as more than rocks, and therefore cannot generate exclusive economic zones or continental shelves, the award also affirmed the Philippines’ sovereign rights within its own waters. Beijing dismissed the final award as a “piece of trash paper,” while a few others questioned the tribunal’s jurisdiction and the merits of the ruling. But contrary to the rhetoric from China and its sympathizers in the Philippines, the arbitration award had a perceptible effect. While it is true that China formally rejected the arbitration outcome, as great powers tend to do with international court decisions, the ruling led to a major shift in its strategy.

After July 2016, Beijing began to avoid mentioning the invalidated nine-dash line claim in formal statements, instead advancing an alternative interpretation of maritime entitlements based on the “four sha,” or island groups it claims in the South China Sea. This theory is yet to be seriously endorsed by any leading legal experts outside of China, and was in fact explicitly rejected by the tribunal which found that the Spratly Islands cannot be treated as a single unit for the purpose of generating maritime claims.

China also moved quickly after the ruling to launch new diplomatic efforts with the Philippines and ASEAN to avoid blowback from its loss. Luckily for China, it benefited in this effort from the inauguration of President Rodrigo Duterte just before the ruling was issued. Duterte chose to “set aside” the arbitration award in favor of warmer economic ties with China. Thus his government has provided some diplomatic cover for China.

Now Vietnam also has the option of using compulsory arbitration to reaffirm its sovereign rights within its own EEZ and continental shelf, including near Vanguard Bank, which was the site of a tense standoff between Vietnamese and Chinese law enforcement vessels that lasted nearly four months earlier this year. The arbitration could also censure China’s acts of aggression within Vietnamese waters and encroachment by Chinese fishers. If Hanoi still considers arbitration too sensitive, UNCLOS also provides the option of a nonbinding but compulsory conciliation commission to attempt to resolve overlapping claims. Either way, UNCLOS provides mechanisms for Vietnam to assert and, based on the Philippine precedent, likely affirm its sovereign rights.

An emphasis on lawfare would not only strengthens Vietnam’s own position, but also that of the Philippines, where a majority of the population (87 percent) wants the Beijing-leaning government to assert the 2016 arbitral ruling. It would also put pressure on the Philippines to ensure that its proposed joint exploration agreement with China is consistent with UNCLOS and the tribunal’s ruling.

As a great power seeking the trust and respect of its neighbors, China is well-aware that lawfare by smaller countries chips away at its case for authoritative leadership in Asia. This creates incentives for Beijing to seek face-saving measures to avoid a repeat of the 2016 loss to the Philippines. Thus Vietnam has good reasons to seriously consider legal countermeasures against China, which could either reaffirm Hanoi’s rights in the South China Sea or help leverage Beijing into seeking compromises.

About Richard Javad Heydarian

Richard Javad Heydarian is an Asia-based academic, currently a Research Fellow at National Chengchi University (Taiwan), and author of, among other works, The Rise of Duterte: A Populist Revolt against Elite Democracy and The Indo-Pacific: Trump, China, and the New Struggle for Global Mastery.