<P> The United States is a founding member of NATO, an alliance of 28 North American and European nations formed to defend Western Europe against the Soviet Union during the Cold War . Under the NATO charter, the United States is compelled to defend any NATO state that is attacked by a foreign power . The United States itself was the first country to invoke the mutual defense provisions of the alliance, in response to the September 11 attacks . </P> <P> The United States also has mutual military defense treaties with: </P> <Ul> <Li> Australia and New Zealand </Li> <Li> Japan </Li> <Li> South Korea </Li> <Li> Philippines </Li> <Li> Thailand, with other states formerly in the Southeast Asia Treaty Organization </Li> <Li> Most countries in South America, Central America, and the Caribbean, through the Inter-American Treaty of Reciprocal Assistance </Li> </Ul> <Li> Australia and New Zealand </Li>

Which of these was an interventionist policy of the united states