Kennedy wanted to start the peace corps for several reasons including:
a) Understanding different cultures.
b) Helping countries who were in need (especially countries with little medical aid).
c) Spread the ideas of peace and democracy around the world.
In this sense, helping other countries who were in need would be the most persuasive argument. Helping other countries by providing highly trained doctors and medical professionals will help to improve the overall well being of humanity. This can be seen as a noble cause and brings a positive image of the United States around the world.
