By Chau Hoang —

An environmental disaster that saw 70 tons of dead fish wash up on Vietnam’s coast in April and which was eventually attributed to toxic factory waste dumped by Taiwanese-owned Formosa Ha Tinh Steel Corp.has sparked weeks of protests by an aggrieved public. Hanoi’s intolerance of open dissent is well-established, and these unusual protests are made all the more striking by the organizer’s ability to unite different elements across the nation. Demonstrators hail from diverse socioeconomic backgrounds and have expressed a variety of motivations, but protests broadly revolve around two coexisting impulses: a thirst for immediate economic redress and an aspiration toward more political reform.

Though the protests against the steel mill have been primarily depicted as a public backlash against an environmental scandal, economic frustrations lie at the core of the movement. Groups especially hard-hit include fishermen, fish sellers, and small beachside business owners whose livelihoods have suffered after the fish kill devastated the local fishing and tourism industries.

The resulting economic crunch has spawned months of protest centered on populist concerns. An April 29 sit-in in the central province of Quang Binh saw a group of fish vendors block the road for hours after dumping baskets of poisoned fish in front of a row of policemen. The movement has shown no signs of subsiding since, with many large demonstrations taking place throughout the summer. On September 1, a crowd of 10,000 people marched six miles in Ha Tinh province, razing barriers erected by local police and displaying slogans that read “Formosa or the People — Pick One.”

Most recently, more than 500 Vietnamese fishermen on September 26 traveled 125 miles from Nghe An province to a provincial court in Ha Tinh to sue the Taiwanese steel firm. The clamor for economic relief has culminated in a legal battle cast in Vietnam’s non-mainstream media as a struggle between an economically destitute people and a predatory state. In railing against a sense of economic injustice, these outbursts reinforce a populist rhetoric that is becoming increasingly familiar in Vietnamese civil discourse.

These economic grievances are intertwined with a nationalistic reaction to external pressures — namely, China’s and Taiwan’s recent investments. Such concerns are not new: Vietnam has long feared China’s rising political and economic dominance in Southeast Asia, while Taiwan’s growing industrial presence in Vietnam has often been conflated with Chinese expansion.

Furthermore, the increasing presence of Chinese workers in the central Vung Ang Economic Zone has been fanning fears of a “Chinese plot” to occupy Vietnam. Whether or not these fears are founded, the nationalist resentment they induce is real. In 2014, for instance, a wave of nationalism erupted in deadly riots across central and southern Vietnam after China moved the Haiyang Shiyou 981 oil rig to waters just off the disputed Paracel Islands in the South China Sea.

The Formosa steel mill disaster and ensuing protests stoked these resentments into a firestorm, casting the Taiwanese company-caused disaster as symptomatic of a Chinese invasion. In a particularly zealous outburst, Catholics in the parish of Phu Yen in southern Vietnam on August 21 chanted “Formosa: out, out, out! Nine-dash line: cut, cut, cut!” — the latter a reference to China’s extensive and controversial claims in the South China Sea.

Other demonstrations also throbbed with nationalist fervor. A video from the April 29 sit-in showed protesters singing a well-known paean to Ho Chi Minh synonymous with the capture of Saigon and victory in the Vietnam War. By glorifying Vietnam while reducing foreign actors to a monolithic adversary, these protests depict a familiar narrative: a populist reaction against economic pressures created by a foreign threat.

Yet the Formosa steel mill incident has also drawn out a different set of aspirations, toward political reform. A motto popular with the protesters, “the fish need clean water; the people need transparency,” evinces the protesters’ prioritization of governance issues at the forefront of their grievances. More radical activists have used the protests as a political platform to challenge the legitimacy of Vietnam’s communist leadership.

This ideological cause has surfaced in various contexts, from scathing blog posts to the renewed popularity of the activist song called “Give Them Back to Us the People,” that protests the 2013 jailing of several regime critics. Nearly all protests now feature the song, calling for “human rights” and the chance to “quash dictatorship.” Though grounded in popular sentiment, this rhetoric appeals to a set of values that transcend immediate economic needs, seeking change not simply in policies but in the political system that forms and enacts them.

Exhibiting both aspirations to political reform and short-term populist motivations, the Formosa steel mill protests occupy an uncertain place in Vietnam’s civil discourse. From Hanoi’s perspective, the mixed motivations behind the protests allow a number of responses: repression, palliative measures to address economic ills, or political reform.

So far, Hanoi’s actions have vacillated between suppressing and appeasing protesters. Yet no concrete reform measure has been proposed, and given Hanoi’s history of intolerance of its critics, the dual tactics of suppression and appeasement may be explicitly designed to preserve the party-state until popular clamor for economic redress dissipates.

Whether the momentum for political change in Vietnam can persist beyond the fulfillment of immediate economic needs is unclear. The Formosa steel mill protests may derive their staying power from their diversity. In unifying elements across socioeconomic and geographic lines, these protests heighten a new division in the Vietnamese political sensibility — that between “the people” and their opponent, whether it be foreign actors or the government itself. Though the prospect of political reform remains uncertain, these protests herald a more politically engaged Vietnamese society, whose increasing alienation from the state may engender a more vigorous culture of dissent.

Ms. Chau Hoang is a former researcher with the Southeast Asia Program at CSIS.