Answer: It is the responsibility of the United States to promote and defend human rights at home and abroad.
Kennedy was well known for his human nature and caring for others, in this speech he says "unwilling to witness or permit the slow undoing of those human rights to which this nation has always been committed, and to which we are committed today at home and around the world."
This tells us that he foresaw a country, an american country comitted to helping those who were suffering injustices, inside america, or around the globe. The states were in a position were Kennedy felt they ought to do something to help around.