Mkutano wa viongozi wa NATO Chicago

Demonstrators flow out of Grant Park in Chicago during this weekend's NATO summit Sunday, May 20, 2012 in Chicago. (AP)

U.S. President Barack Obama during a meeting with Afghanistan's President Hamid Karzai at the NATO Summit at McCormick Place in Chicago, May 20, 2012. (Reuters)

NATO leaders pose for a family photo outside Soldier Field in Chicago. (Reuters)

NATO Secretary-General Anders Fogh Rasmussen arrives at the Summit in Chicago, May 21, 2012. (Reuters)

从林肯纪念堂遥望华盛顿纪念碑

A demonstrator sits in a tree Grant Park before a march in Chicago. (AP)

A Chicago Police officer confronts a protester during a march and rally at this weekend's summit. (AP)

German Chancellor Angela Merkel talks to President Barack Obama as she arrives in Chicago, Sunday, May 20, 2012. At left is NATO Secretary General Anders Fogh Rasmussen. (AP)

President Barack Obama and British Prime Minister David Cameron help Secretary General Anders Fogh Rasmussen find his toe marker. (AP)

Valerie Trierweiler, partner of French President Francois Hollande, and first lady Michelle Obama watch a student explain the making of a meal during a tour of the Gary Corner Youth Center in Chicago. (AP)

A protestor covered in silver paint purchases a rail ticket following an anti-NATO protest march. (Reuters)