Answer:
The two Southeast Asian countries that were a part of SEATO were Pakistan and Thailand.
Step-by-step explanation:
The Southeast Asia Treaty Organization (SEATO) was an international collective defense organization created by the Manila Pact, signed on September 8, 1954. The formal organization of SEATO was established at a meeting in Bangkok, Thailand, in February 1955, where its headquarters was established, its main purpose being to block possible communist advances in Southeast Asia. The organization was dissolved on June 30, 1977.
The organization was intended to be an Asian version of NATO, in which the military forces of each of its members would be coordinated to jointly defend each of the signatory countries. SEATO used parts of the armed forces of each member country for annual joint military maneuvers.
It consisted of eight countries: Australia, France, New Zealand, Pakistan, the Philippines, Thailand, Great Britain, and the United States.