In the groundwork for the metaphysics of morals we find that to act on duty is to act from a self-seeking purpose to act because you want to to act out of respect for law to act out of the fear of god

the answer is

a) revise existing treaties

b) do away with political alliances

c) prevent the spread of communism

d) bring an end to european colonization

the main goal of the southeast asia treaty organization was to prevent the spread of communism in southeast asia.