NATO Leaders Gather In Chicago

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

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.

Leaders watch a ceremony honoring NATO military personnel for their service the NATO Summit meeting in Chicago, May 20, 2012.

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

A demonstrator sits in a tree Grant Park before a march in Chicago, May 20, 2012.

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

German Chancellor Angela Merkel talks to President Obama at the Summit. At left is NATO Secretary General Anders Fogh Rasmussen.

Leaders pose for a family photo outside Soldier Field, May 20, 2012.

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

Valerie Trierweiler, partner of 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.

A protester covered in silver paint purchases a rail ticket following an anti-NATO protest march in Chicago, May 20, 2012.