A frame grab from a video released by the Islamic State shows an IS militant holding a knife before purportedly executing British aid worker David Cawthorne Haines. Islamic State Video/EPA /LANDOV hide caption

itoggle caption Islamic State Video/EPA /LANDOV

The prime minister's "red box," looking rather lonely, on a train Saturday from London to York. The Mirror made it front page news. The Mirror hide caption

itoggle caption The Mirror

British Prime Minister David Cameron, who says it is time for the U.N. Security Council "to live up to its responsibilities on Syria." Stefan Wermuth /Reuters /Landov hide caption

itoggle caption Stefan Wermuth /Reuters /Landov

The G-8 leaders speaking at this news conference in Northern Ireland all lost their ties, but British Prime Minister David Cameron (right) went a step further by ditching his jacket and rolling up his sleeves. Andrew Winning/WPA Pool/Getty Images hide caption

itoggle caption Andrew Winning/WPA Pool/Getty Images

President Obama and British Prime Minister David Cameron in the Oval Office of the White House on Monday. Jim Watson /AFP/Getty Images hide caption

itoggle caption Jim Watson /AFP/Getty Images

British Prime Minister David Cameron (left) and Russian President Vladimir Putin viewed the Sochi Olympic Park along the Black Sea coast by helicopter Friday. Nikolsky Alexei /ITAR-TASS /Landov hide caption

itoggle caption Nikolsky Alexei /ITAR-TASS /Landov

A rebel fighter raises his weapon after firing a missile Sunday toward Syrian government troops in the northern city of Aleppo. Syria's largest city has been the scene of heavy fighting for the past three months. Both sides control part of the city, and the fight has been a stalemate recently. Narciso Contreras/AP hide caption

itoggle caption Narciso Contreras/AP