A new poll by the Pew Research Center for the People and the Press suggests a significant negative shift in perceptions of the United States among people in 44 nations, including many in the Muslim world. But as NPR's Vicky O'Hara reports, the poll also exposes many contradictions. Much of the world, for example, believes that Iraq is a threat to Mideast stability -- but are suspicious of American motives. Read the results of the entire poll.