What is the author's purpose in the above passage, and how does she achieve it through her organization and choice of details?

The sentences in this excerpt from Franklin D. Roosevelt’s "Four Freedoms" speech suggest that going to war will result in a peaceful political system is:

This nation has placed its destiny in the hands and heads and hearts of its millions of free men and women; and its faith in freedom under the guidance of God. Freedom means the supremacy of human rights everywhere. Our support goes to those who struggle to gain those rights or keep them. Our strength is our unity of purpose. To that high concept there can be no end save victory.