UNITED NATIONS — A top executive of the U.N. development arm threatened "retaliation" against a State Department official this week even though America, the top financier of the agency, pays $100 million of its annual budget. In Washington, meanwhile, a new piece of legislation introduced in Congress yesterday set reform benchmarks for the United Nations to achieve — or else risk the withdrawal of American funds. Along with growing disenchantment with the human-rights system, these developments raise the possibility of a new chill in relations between Washington and Turtle Bay. In a strongly worded letter to the administrator of the...