In the chaotic aftermath of the First Indochina War and the 1954 Geneva Accords, South Vietnam teetered on the edge of fragmentation. The newly appointed Prime Minister Ngô Đình Diệm faced not only political opposition but powerful non-state actors who commanded private armies, controlled cities, and challenged the very idea of a centralized government. Among the most formidable of these were the Bình Xuyên and the Hòa Hảo – groups Diệm would have to confront militarily and politically in his campaign to establish control over the fledgling state.
The Bình Xuyên: Breaking Saigon’s Underworld Army
The Bình Xuyên, led by crime boss Bảy Viễn (Lê Văn Viễn), operated like a mafia-state within South Vietnam. With an estimated force of up to 25,000 men, they controlled Saigon’s police, ran lucrative vice operations (gambling, prostitution), and enjoyed support from the French, who saw them as a counterweight to Vietnamese nationalism.
Step 1: Political Chess (1954–1955)
Diệm, appointed prime minister in June 1954, inherited a government riddled with French-backed factions. The Bình Xuyên were deeply embedded in the State of Vietnam’s security apparatus under Emperor Bảo Đại, and they fiercely resisted Diệm’s authority.
To counterbalance French influence, Diệm secured the backing of the United States, particularly through CIA advisor Edward Lansdale, who helped shape public opinion and encouraged the loyalty of key officers in the Vietnamese National Army (VNA).
Step 2: The Crisis Escalates (March 1955)
In March 1955, Diệm demanded the Bình Xuyên relinquish control of the police and merge their forces with the national army. Bảy Viễn refused. Tensions exploded on March 29, when Bình Xuyên forces shelled the Norodom Palace. Diệm responded swiftly, replacing their police officers and preparing for full-scale conflict.
Step 3: The Battle of Saigon (April 27 – May 2, 1955)
Diệm launched a decisive offensive. VNA troops stormed Bình Xuyên strongholds in Saigon and nearby Cholon, engaging in days of intense urban combat. Artillery barrages destroyed entire neighborhoods, and civilian casualties were heavy – estimated between 500 and 1,000, with thousands more displaced.
The Bình Xuyên were outmatched. The VNA’s superior firepower and discipline overwhelmed them. Bảy Viễn fled to Cambodia, and the group’s network crumbled.
Step 4: Securing the Capital
With the Bình Xuyên defeated, Diệm replaced their police force with loyalists, shut down their gambling dens, and redirected income to the state. This victory not only ended a major internal threat but also cemented Diệm’s grip on Saigon, allowing him to centralize power and present himself as a capable leader.
The Hòa Hảo: A Religious Sect Turned Rebel Force
The Hòa Hảo, a Buddhist millenarian movement, had long maintained armed independence in the Mekong Delta. Their leaders, including Ba Cụt (Lê Quang Vinh) and Trần Văn Soái, commanded thousands of fighters and demanded autonomy from any central government.
Divide and Rule (1954–1955)
Diệm initially tried a divide-and-conquer approach. Some Hòa Hảo leaders, like Trần Văn Soái, were co-opted through offers of military rank and government positions. But Ba Cụt remained defiant, commanding an estimated 4,000-10,000 fighters and continuing to operate as a warlord.
The Military Campaign (1955–1956)
Once the Bình Xuyên were neutralized, Diệm turned to the Mekong Delta. In mid-1955, the VNA launched operations targeting Ba Cụt’s strongholds around Long Xuyên and Cần Thơ. Skirmishes continued into 1956, gradually wearing down rebel forces. Some Hòa Hảo fighters accepted amnesty, while others were defeated in combat.
The Fall of Ba Cụt (1956)
In April 1956, Ba Cụt was betrayed by a subordinate and captured. In July, Diệm ordered his public execution by guillotine – a dramatic and symbolic act meant to discourage further rebellion.
Aftermath and Integration
Diệm continued to integrate cooperative Hòa Hảo figures into his administration while garrisoning loyal troops throughout the Delta. By 1957, the sect no longer posed a military threat, though some disaffected followers would later join anti-government movements, including the Viet Cong.
The Cao Đài and the “United Front”
Around this time, Diệm also moved against the Cao Đài, another powerful religious sect with its own militia. Though briefly aligned with the Bình Xuyên and Hòa Hảo in a so-called United Front, the alliance was fragile and short-lived. Diệm used similar tactics – co-optation and force – to dissolve their military structure and pull them under central control.
Keys to Diệm’s Success
- U.S. Backing: American funds, advisors, and political support emboldened Diệm to challenge entrenched power blocs.
- Army Loyalty: Diệm cultivated relationships with VNA officers, ensuring the army remained his instrument of control.
- Divide-and-Conquer Tactics: He exploited rivalries among sect leaders, weakening resistance from within.
- Use of Force: Diệm did not shy from decisive – and sometimes brutal – measures to eliminate opposition.
Consequences and Legacy
Diệm’s victory over the Bình Xuyên, Hòa Hảo, and Cao Đài allowed him to consolidate power and declare the Republic of Vietnam in October 1955, after a referendum that removed Bảo Đại from power. Saigon became a more stable capital, and the threat of warlordism was largely eliminated.
But stability came at a price. Diệm’s increasingly authoritarian rule, favoritism toward Catholics, and suppression of political dissent alienated Buddhists and rural communities. The seeds of future rebellion were planted in this very moment of victory.
In retrospect, Diệm’s triumphs bought South Vietnam critical time – but his governance ensured that time would not be used to build an inclusive or sustainable political order.

Ngo Dình Diem and other people, including ministers of the first government of the Republic of Vietnam
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