Police officers attempt to detain a protester during a march leading up to the NATO Summit in Chicago May 18, 2012. The Summit runs from May 20-21. Leaders from members of the NATO alliance are expected to discuss the worsening situation in Afghanistan, and protest organizers said they hope thousands of people will turn out to demonstrate against the war and other issues such as income inequality. REUTERS/Eric Thayer (UNITED STATES - Tags: POLITICS BUSINESS)