During the 1960s and 1970s, Chavalit served in the communist insurgency suppression campaign in the jungles of Thailand, and prepared Thai soldiers for their operations in the Vietnam War.

[7] However, Chavalit believed that the communists could not be defeated by purely military means, but that combating the political, economic and social causes of the insurgency was also necessary to destroy their popular support.

He helped to author cabinet orders 66/2523 (1980) and 65/2525 (1982) of Prem Tinsulanonda's government, which offered amnesty and a return to civil life to surrendering communist fighters.

[6] Chavalit's rise to the army's top posts was unusual for a signal corps officer, as its leading positions were traditionally reserved for infantrymen, artillerymen, and "cavalrymen" (i.e., tankers).

He owed his exceptional career partly to his close relationship to Prime Minister Prem, being one of his core supporters in the army, but also to his military, strategic, and political acumen.

[14] Chavalit used contacts from his time as army commander and head of the "Green Isan" programme to recruit former soldiers, civil servants, and local officials in the Northeast as members of his party.

However, during his premiership he encountered pressure from many political movements, who forced him to resign on 6 November 1997, in the midst of the Asian financial crisis.

This sparked the Asian financial crisis, due to the Thai government's failure to defend the baht against international speculators.

At the time, Thailand had acquired a burden of foreign debt that made the country effectively bankrupt even before the collapse of its currency.

According to some observers, King Bhumibol Adulyadej distrusted Chavalit as he saw him as a threat to his so-called "network monarchy", an informal alliance of politicians and officials favoured by the palace.

After New Aspiration's electoral defeat in 2001, Chavalit abandoned it and switched over to the TRT, taking most party members and lawmakers with him.

After holding the position of deputy prime minister in Somchai Wongsawat's cabinet, on 7 October 2008, he resigned, admitting partial responsibility for violence because of police use of tear gas at a Parliament blockade, injuring 116 protesters.

"[19][20][21] On 2 October 2009, Chavalit joined the Pheu Thai Party, which was composed of loyalists to Thaksin Shinawatra.