US Ambassador John Bolton strongly rebuked remarks by a senior UN official criticizing Washington's stance on key UN issues, demanding that they be repudiated to avoid doing serious damage to the world body. In a speech delivered Tuesday at a New York conference on global leadership, UN Deputy Secretary General Mark Malloch Brown slammed what he called the prevailing US "practice of seeking to use the UN almost by stealth as a diplomatic tool while failing to stand up for it against its domestic critics." "To acknowledge an America reliant on international institutions is not perceived to be good politics...