Page 222 in American Empire.
“The United States had very few economic or other interests in Vietnam before the war, little knowledge of it, and no particular expectation that a victory would bring deep or profitable engagement . American policymakers acted primarily out of ideology and a strategic outlook that saw any shift of control or power away from the United States, no matter where it occurred, as threatening its interests and security everywhere.”
I think this quote was included because it summaries a little reasoning behind the war against Vietnam. Later on in the chapter it discusses the reason. It became involved in Vietnam because of the relationship the United States has with France and many other wars, small details that eventually led to the conflict. I think Freeman thinks this part is important because it shows the status of America during that time and how if it felt threatened, they will make sure it will remain stable.