[caption id="attachment_152320" align="alignright" width="185"] U.S. Secretary of State John Kerry reacts during a media briefing at the U.S. Embassy in London, February 21, 2015.CREDIT: REUTERS/NEIL HALL (BRITAIN - TAGS: POLITICS)[/caption] (Reuters) - U.S. Secretary of State John Kerry and his Iranian counterpart Mohammad Javad Zarif will try ...