This study has shown the extent to which the Thai military has dominated the country's internal security affairs since the Cold War period. ISOC is not the only agency in charge of internal security, but the whole armed forces, and the army in particular, are devoted to the mission. ISOC has coordinating and commanding authority over the police and other civilian agencies. ISOC can utilize the robust infrastructure of the army units as well as various civilian bureaucratic agencies. The modern Thai armed forces have never engaged in large-scale warfare with an external enemy since their formation in the early twentieth century. Internal security is the raison d’être of the Thai armed forces and the source of its expanding scope since the counterinsurgency period, defining its role and lending it authority over national institutions and the people.

The political offensive approach against the communist threat opened up a path for the military to engage in the nation's socio-economic and political development. Under successive military governments, the army took over political affairs. On the one hand, the operations allowed the army to lead and coordinate other state agencies in the counterinsurgency. On the other hand, the integration of development projects, mass organizations, ideological indoctrination and propaganda programmes into its operations consolidated the army's role and authority in the nation's socio-economic and political affairs.

The line that distinguishes internal security from normal domestic affairs became increasingly blurred in the post-counterinsurgency period. The definition of internal security became much broader on grounds of meeting new threats in a volatile world. Many new security threats were non-combatant in nature, yet the Thai military folded them into its mission. From fighting communist insurgency, its mission extended to defending and promoting the monarchy, eradicating poverty, managing democratization, protecting natural resources, combatting human and drugs trafficking, and building political unity. A new term was created to disguise the military's political strategy: counterinsurgency operations was supplanted by civil affairs.

The internal security mechanism became a political tool of the military and its conservative allies to protect and perpetuate their political domination and suppress political dissidents.