Democratic presidential candidate Robert F. Kennedy, Jr., in what he billed as a “major foreign policy speech,” is calling for a fundamental transformation of American foreign policy that can be summed up in one word: peace.

In a speech in New Hampshire Tuesday night, Mr. Kennedy called for a diplomatic solution to the war in Ukraine and an end to military adventures abroad. He peppered his speech with anecdotes and quotations from his late uncle, President John F. Kennedy, to frame his calls for peace as a continuation of President Kennedy’s policies.