The attacks marked a sharp escalation of the U.S. military campaign as Islamic State fighters threatened to seize a dam that generates electricity for much of Iraq.
More:
http://www.washingtonpost.com/world/us-launches-new-airstrikes-against-islamic-state-fighters-in-iraq/2014/09/07/bfae8762-35ff-11e4-a723-fa3895a25d02_story.html?hpid=z1