(Reuters) - United Nations peacekeeping missions routinely avoid using force to protect civilians who are under attack, intervening in only 20 percent of cases despite being authorized to do so by the U.N. Security Council, an internal U.N. study found. "There is a persistent pattern of peacekeeping operations not intervening with force when civilians are under attack," the report by the Office of Internal Oversight Services said. "Peacekeepers are absent from many locations when civilians come under attack, and when they are present, are unable or unwilling to prevent serious physical harm from being inflicted," the 26-page report said. :snip:...