During World War II, he participated in the Burma campaign, leading forces in the invasion of the Shan State under General Phin Choonhavan.

Known for his strict discipline and effective leadership, Sarit quickly rose through the ranks and established himself as a prominent figure within the military after the war.

After the 1947 coup d'état, Sarit became a key political figure in Phibun's government and played an active role in suppressing the Palace Rebellion of 1949.

By the 1950s, Sarit emerged as a central figure in the "Triumvirate" alongside Phao Siyanon and Phibun, as they competed for dominance in Thai politics.

Sarit's influence grew significantly after the February 1957 election crisis, during which he led a coup that ousted Phibun and temporarily assumed leadership as the head of the Revolutionary Council.

Domestically, Sarit promoted a strong sense of Thai nationalism and emphasized the importance of the monarchy, which became central to his administration's legitimacy.

During World War II he served as commander of an infantry battalion and took part in the invasion and occupation of the Shan States in Burma.

[3] As a colonel, he played a leading role in the 1947 military coup that overthrew the government of Prime Minister Thawal Thamrong Navaswadhi, a protege of Pridi Phanomyong, reinstalling the previously deposed Field Marshal Luang Phibunsongkram as premier.

The government's Legislative Committee was revamped into the Seri Manangkhasila Party which was headed by Phibun with Sarit as deputy chief and Phao as secretary-general.

[3]: 106–107  In a bid to repress public discontent, Phibun declared a state of emergency and Sarit was appointed as the supreme commander of military forces.

[6] The Minister of Agriculture, Field Marshal Phin Choonhavan, said that northeasterner's migration to the city and their consumption of frogs and lizards was normal and that there was nothing to worry about.

In a final attempt to resolve the issue, the Phibun government allocated 53 million baht, which was to be divided equally among the 53 Isan representatives.

Things further escalated when Thiem Khomrit, Director-General of the Forestry Department, was forced to resign and was charged with administrative incompetence.

Thiem further revealed that the Seri Manangkhasila Party had submitted an early application for a license to cut down trees in the area.

The crowd, which quickly grew in numbers, marched to Sarit's residence to show support for the army's demands.

In his speech, Sarit said, "In the name of the army and deputies of the second category, I have conducted my activities based on popular will, and the interests of the people — your coming here gives me moral support to continue.

Likhit's analysis shows how Sarit combined paternalistic rule from the Sukothai (phokhun) with Ayuthaya's despotic power to create his personal political style.

Within days of the coup, electricity rates were lowered[16] and families living in the water-scarce Bangkok-Thonburi area were given 300 large buckets of water free every month.

[17] To help the needy, the Revolutionary Council ordered the municipal government to abolish certain taxes, charges for official service, and license fees.

Hospitals were ordered to give out free medicine and healthcare to the poor, while student nurses and social workers were instructed to make house calls to help with child delivery and health problems.

[18] In a bid to show that everyone was participating in the revolution, the navy was called on by Sarit to provide cheap coconuts to be sold to the public.

Using M17, parliament was abolished, newspapers were strictly censored, political parties were prohibited, and people who were suspected of colluding with communists were imprisoned.

Five were given death penalty for arson, one for heroin production, one for spearheading a messianic uprising, and four on charges of communism, including the activist and former MP Khrong Chandawong.

[27] Thak suggests that Sarit's strict rule can be understood as the modern phokhun style of leadership, where the benevolent leader intervenes to help his people.

The practice of prostration, with the head touching the ground before royal audiences, banned decades earlier by King Chulalongkorn, was reinstated.

In this instance, the throne acted as a charity, collecting funds from private donors, channeling them into public programs that enhanced both the regime's and the monarchy's reputation.

Thai language newspapers published the names of 100 women who claimed to have shared his bed, shocking the public when his corruption was uncovered.

[33]As usual with senior Thai military officers and politicians, Sarit received many royal decorations in the Honours System.