It has been obligatory for American presidents to give lip service to the "value" of the United Nations as an organization vital for world peace. U.N. diplomats love to hear that kind of stuff because they think it justifies their massive expense accounts and other perks that come with living high on the hog in New York City. Donald Trump will pay a visit to New York this week. He will address the U.N. General Assembly on Tuesday (where many representatives are expected to sit on their hands or walk out) and then chair a meeting of the Security Council...