The united states shall guarantee to every state in this union a republican form of government, and shall protect each of them against invasion. according to this quote, the job of protecting the nation from foreign enemies belongs to

The national government

Explanation:

Because oft his , the government was given with the full power to mobilize the military that is funded through tax payers' money. The threats that included under U.S constitution does not only cover the foreign invasion that come from outside of the country. The constitution also require the government to protect the citizens from the threats that come from internal part of the country.

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.