How does the conclusion contribute to the overall text? (Paragraphs 11-14)

The function of your paper's conclusion is to restate the main argument. It reminds the reader of the strengths of your main argument(s) and reiterates the most important evidence supporting those argument(s).  This reduces the impact of the argument(s) you have developed in your essay.

they thoght they were going to nuke each other

the quote by walter cronkite contributes to the central idea of the text by supporting the central idea. cronkite argues that what is deemed “right” for and in america may not be good for other countries. this supports the central idea of the text, that the vietnam war was unpopular in america for multiple reasons- including cronkite’s.