Why did the federal government combine several agencies into the department of homeland security?

How did the southeast asia treaty organization (seato) carry out the united states policy on containment? a. seato promoted the creation of united nation military bases to create regional defense. b. seato founded an organization seeking to educate southeastern asian countries on communism. c. seato established a regional economic union to promote monetary security. d. seato sought to provide regional security in southeast asia by establishing alliances.