Vietnam's one-party, Communist system was once known for its predictability. But President Vo Van Thuong's abrupt resignation on Wednesday — after just a year in the post, making him the shortest-serving president of the communist state — points to increasingly chaotic politics in Hanoi. 

The Vietnamese Communist Party's Central Committee met on Wednesday to accept Thuong's resignation due to "violations" and "shortcomings," the Communist Party has officially said.

The resignation was also approved by the country's parliament on Thursday.

Many Vietnam-watchers had been predicting his downfall for weeks.

Thuong is now the second president to resign in as many years amid a massive anti-corruption crackdown that has taken down many of the Southeast Asian nation's top politicians.

Over the past 18 months, not only have two presidents been forced to resign, but two deputy prime ministers and another member of the Politburo have also been dismissed. The Politburo that was selected at the last National Congress in 2021 has been cut from 18 members to 14, making it the smallest in recent history.

What's behind the president's downfall?

Thuong's downfall is likely the result of ongoing investigations involving the real estate firm Phuc Son Group, which is accused of flagrant corruption in Quang Ngai province, of which Thuong was party chief between 2011 and 2014.

According to some media reports, one of Thuong's relatives is accused of accepting a €2 million ($2.18 million) bribe from the real estate group. The current People's Committee chairman of Quang Ngai province, Dang Van Minh, and the former chairman, Cao Khoa, were arrested in early March over this scandal.

Nguyen Xuan Phuc, Thuong's predecessor as president, resigned last year for the "violations and wrongdoing" by officials under his control, which are believed to refer to corruption in government during the COVID-19 pandemic.

Thuong entered office claiming that he was "determined to fight corruption" in line with the so-called "blazing furnace" anti-graft campaign of Nguyen Phu Trong, the general secretary of the Communist Party.

Although Trong became party chief in 2012, he only consolidated his power in 2016 after defeating his main rival, then prime minister Nguyen Tan Dung, at that year's National Congress.

Dung was widely seen as a figurehead of a faction of the Communist Party that was perceived as accepting corruption as a way of binding the party apparatus together. It was also seen as eschewing socialist ideology.

Why are there political instability concerns?

Trong, who spent most of his career in the Communist Party's theoretical wing, has sought to restore ideology and "socialist ethics" to the foreground of politics, and unleashed a vast anti-corruption campaign that has now taken down many of the country's most powerful politicians.

While that campaign has to some degree cleaned up politics, it has also unhinged the norms and stabilizing mechanisms of Vietnam's repressive and hierarchical one-party system, leading to ever greater instability.

Ever since the 1990s, the Communist Party has functioned by accepting a number of unwritten and codified rules, including a two-term limit for senior politicians, a retirement age of 65 and a separation of powers between the country's four main political posts.

In 2018, Trong tore up the latter rule when, in addition to being party chief, he temporarily became president, following the sudden death of the incumbent head of state.

Three years later, he won a near-unprecedented third term as general secretary despite being 77 years old at the time, well past the expected age of retirement.

However, he is thought to have suffered a stroke in 2019, and his apparent ill-health was a source of rumor in January when he failed to make a public appearance for several weeks.

His desire to make the party chief even more powerful than usual and to consolidate authority among a small coterie of loyalists has upped the stakes of political succession, now that Trong is widely expected to resign at the next National Congress in 2026. Whoever replaces him will have far more power than most previous general secretaries.

"A consequence of Trong's violation of the party's rule, plus his poor health, is an increasing uncertainty about the succession process," said Tuong Vu, professor and director of the US-Vietnam Research Center at the University of Oregon.

"This in turn greatly affects the stability of the regime because various factions are trying to gain an advantage so that their members can take the top positions in the next Congress," he told DW.

Suspicious timing?

While Thuong's resignation was over alleged corruption when he was the party chief of Quang Ngai province almost a decade ago, some have questioned whether these allegations were really news to the Communist Party bigwigs who approved his appointment as president last year, suggesting that the timing of his forced resignation is suspicious.

"Someone was really digging into his past, which suggests that it was politically motivated," said Zachary Abuza, a professor at the National War College in Washington. 

As is usual within the Communist Party, the senior leadership has recently started conversations over the personnel decisions that will be made at the next National Congress, expected to take place in the earlier months of 2026.

They will now have to decide on Thuong's replacement as president. If the Communist Party sticks to its own regulations that the new president must have served a full term as a member of the Politburo, there are only five candidates, although it is possible that it will bend the rules once again.

Prime Minister Pham Minh Chinh and National Assembly Chair Vuong Dinh Hue are unlikely to be interested, since the presidency is a lower position in terms of political power than their current offices, noted Le Hong Hiep, a senior fellow at the ISEAS–Yusof Ishak Institute's Vietnam Studies Program in Singapore.

Who could succeed Thuong?

To Lam, the powerful minister of public security, is an option and the presidency may make it easier for him to get an exception to the age limit rule in order to run for the general-secretary post in 2026.

However, moving to the presidency will reduce his ability to steer the anti-corruption campaign, thus potentially harming his ambitions to take the top job.

Analysts reckon the presidency will likely be taken up by Truong Thi Mai, standing member of the Communist Party's Secretariat, Trong or someone further down the pecking order. 

This choice will also have some impact on who replaces Trong, the general secretary, in 2026, the source of much of Vietnam's political instability. 

Thuong was one of only five eligible candidates to succeed Trong, Abuza noted. With his stepping down, there are just four candidates left.

However, Hiep said, Prime Minister Chinh has his own corruption allegations hanging over him, and Mai has a "relatively weak power base."

That leaves To Lam, who heads the anti-corruption campaign, in pole position, leading some to suspect that the public security minister might have had a hand in the downfall of his colleagues.

"To Lam clearly played a role in the resignation of Vo Van Thuong, and before him, Nguyen Xuan Phuc," said Vu of the University of Oregon.

"The anti-corruption campaign has allowed To Lam to amass personal power, leaving him now, if he wants to, as the highly likely successor to Trong if he steps down at the next Congress," he added.

Edited by: Srinivas Mazumdaru