Nguyen Chi Tuyen, also known as Anh Chi, was detained in Vietnam under anti-state charges on Thursday.

The YouTube influencer is being investigated for disseminating information against the Vietnamese state and will spend four months in detention in Hanoi while authorities conduct their inquiries.

Tuyen is one of Vietnam's most known civil society activists. He was part of the "No-U group," an anti-China group that rejected Beijing's U-shaped line in its attempts to control territory in the South China Sea.

Focusing on key influencers

Tuyen has successful YouTube channels, including one on which he discusses foreign affairs — including Russia's war in Ukraine.

Zachary Abuza, a professor at the National War College in Washington D.C. who focuses on Southeast Asia politics and security, said the YouTuber was the latest influential activist to be targeted.

"For independent journalists, there has been a swath of cyber laws, decrees, and policies that have raised the costs, imposed civil fines, and shifted the onus to policing to the social media platforms themselves," he told DW.

"Through these measures, the government hopes that self-censorship will do most of the work for them."

"The Ministry of Public Security has focused its attention more on the key influencers," he added.

'Ensuring national security'

Vietnam is a one-party Communist state in Southeast Asia whose government has complete control over the state's functions, social organizations and media.

Although Vietnam has a fast-growing economy, the country still has a poor reputation on corruption, political censorship, human rights and civic society.

In February, leaked documents from Vietnam's Politburo, the highest decision-making government body, revealed a rare insight into the thinking of its leaders.

It showed how the Vietnam government's policies aim to "ensure national security," including preventing civil society from shaping the country's policies and creating opposition groups.

The dossier Directive 24 was obtained and translated by The 88 Project, a US-based organization that campaigns for freedom of expression in Vietnam.

As of today, there are 176 activists in Vietnamese prisons, according to the project.

"Nguyen Phu Trong has been single-mindedly focused on taking Vietnam's nascent civil society apart. He's gone after sector by sector, including the bar association, environmentalists and independent journalists. Directive 24 encapsulates his thinking about the threat posed by civil society in leading a colored revolution," Abuza said about the head of the Politburo.

But Vietnam's high-level meetings with two of the world's major superpowers have also played a part in Hanoi's growing assertiveness over its domestic policies.

The United States and Vietnam upgraded their ties to "comprehensive strategic partners" in September following a visit to Vietnam from US President Joe Biden.

"Hanoi has been emboldened by the fact that there have been two US administrations that have not raised human rights as a bilateral issue," Abuza said.

"Trump simply didn't care. The Biden administration said that human rights would be central to its foreign policy, but in its courtship with Hanoi, it has all been ignored."

Chinese leader Xi Jinping also visited Hanoi in December to discuss the two countries' "shared future."

"Vietnam does learn from China when it comes to developing laws and regulations to monitor the internet — but the leaders in Hanoi are in a bind as the internet, unlike China, is open and Vietnam is a much more open society than China," Abuza added.

"The Communist Party of Vietnam leaders have the same concerns as China, but they don't have all the coercive measures, so there is a degree of paranoia."

Climate activists 'tread on important toes'

Environmentalists have also said they have faced intimidation and harassment from Vietnamese authorities, and many who have challenged the government's energy policies have ended up being sentenced to prison terms for "tax evasion" or "fraud" — a common tactic of repression by Vietnam's communist government.

The 88 Project said there is evidence that the activists were imprisoned to silence their voices and remove them from society.

Bill Hayton, associate fellow at Chatham House Asia-Pacific in London, said at the time that activists tend to "tread on important toes."

Hayton told DW that "by criticizing the state-owned coal industry, they are upsetting powerful domestic interests in Vietnam. And that's brought them some enemies."

Edited by: Keith Walker