Nguy Thi Khanh, a prominent activist and the first Vietnamese recipient of the prestigious Goldman Environmental Prize, was arrested by the police in February.
On June 17, she was sentenced to two years in prison after being found guilty of "tax evasion," a new tactic of repression by the country's communist government.
Khanh, part of a team of civil-society actors informally overseeing the implementation of the EU-Vietnam free trade deal, rose to fame in 2016 after pressuring the government to commit to cutting 20,000 megawatts of coal power from energy plans by 2030.
The US and the EU have called for her release, while her case has left political commentators to speculate on Hanoi's commitment to environmental protection.
In early June, the British magazine The Economist dubbed Vietnam "a bright spot on an otherwise soot-black map" for climate change action in Southeast Asia. In 2021, it became one of the top 10 producers of solar power in the world, according to the International Renewable Energy Agency.
The share of its electricity generated by solar increased from almost zero in 2017 to nearly 11% last year.
Vietnam's government has vowed to stop building new coal-powered plants and, at the UN climate summit in Glasgow last year, Prime Minister Pham Minh Chinh said coal consumption would end by 2040.
He said he also wanted to cut emissions to net-zero by 2050, an uphill struggle, given that the country's energy needs are set to increase as its economy grows rapidly and citizens become more prosperous.
Hundreds of activists in prison and 'at risk'
Nguyen Khac Giang, an analyst at the Victoria University of Wellington, said Khanh's imprisonment didn't represent "any negative turn in Vietnam's green credentials or environmental policy."
"Rather, this is well in line with the regime's tightening control of civil society in general and NGOs in particular in the past five years," Giang said.
He said another prominent NGO leader, the labor-rights activist Dang Dinh Bach, was sentenced to five years in prison in January for similar charges. The journalist Mai Phan Loi also recently received a four-year prison term for alleged tax fraud.
Vietnam, a one-party state, is one of the most repressive countries in Asia. The 88Project, a monitoring group, estimates that at least 208 activists are currently in prison, and another 340 are on its "at risk" list.
Khanh was arrested in early February, on the same day that the Hanoi People's Court sentenced two other well-known environmental activists, Mai Phan Loi and Bach Hung Duong, to lengthy prison terms.
Although "tax evasion" is used to discredit influencers and vocal critics of the regime, "it's assumed that Khanh got jailed because of her fierce advocacy for coal phaseout," said Jessica Nguyen, advocacy officer of the 88Project.
Khanh, for instance, was a well-known critic of the country's draft Development of Power Plan VIII, which is accused of not doing enough to tackle environmental challenges.
Although the Communist Party is committed to action on climate change, it opposes too much public participation in this process, analysts say. It wants change to be top-down. And it is extremely wary of criticism about its coal policy since public momentum against coal could impact its overall economic policy.
Khanh was likely "too bold and successful for the taste of Vietnam's ruling party, a Communist group of people who dislike competition for the attention of ordinary Vietnamese people," Nguyen said.
Environmentalism poses problem for Communists
Overtly pro-democracy activism is rare in Vietnam, although several large groups and movements have been formed in recent years to agitate for a multiparty system. All were swiftly shut down by the authorities and their leaders jailed.
Environmentalism poses a much more difficult problem for the authorities, analysts say. The Communist Party cannot easily accuse climate change activists of being unpatriotic since most of the activism centers around protecting Vietnamese land.
Environmentalism is deeply intertwined with nationalist causes in Vietnam. After a Taiwanese-owned steel plant spilled tons of toxic waste in 2016 that spoiled waterways across much of central Vietnam, activists accused the government of not acting patriotically enough to respond to the environmental disaster.
Neither can the government easily accuse the environmental activists of being a threat to the regime: Most campaign for reform rather than wholesale change to the political system.
As a result, the authorities have become more creative in how they silence environmental campaigners. The murky world of taxation, especially as tax rules on NGOs are ill-defined, appears to be their solution.
Impact on Vietnam's ties with US and EU
Khanh was the founder of the Green Innovation and Development Center, a local civil-society group. She also sat on the board of the VNGO-EVFTA network, an informal group of organizations supposed to monitor the implementation of the EU-Vietnam free trade agreement.
On June 19, the US State Department called on the Vietnamese government to release Khanh, "as well as other detained environmental activists working for the benefit of Vietnam and its people."
The following day, Nabila Massrali, the EU spokesperson for foreign affairs, tweeted out the bloc's response. "Khanh is a valuable partner for the EU. Her recent sentencing to two years in prison goes against our common goal. We call for her immediate release," it stated.
An EU spokesperson told DW that it "will continue to raise [Khanh's] case with the Vietnamese authorities, including in the context of forthcoming discussions on the Just Energy Transition Partnership," a worldwide EU scheme.
The EU spokesperson noted that Khanh's representatives have appealed against her imprisonment. Several prominent jailed Vietnamese activists have been released in recent years on the condition they go to live in exile either in the US or Europe.
Edited by: Srinivas Mazumdaru