A wounded member of the Afghan police reaction force waits for treatment in Alingar, Laghman province, on April 30, 2012. A bomb exploded next to opium poppy fields during a poppy eradication campaign in, wounding two Afghan policemen, police officials said. (AP Photo/Rahmat Gul)

A burning tank is in Daraa, on March 9, 2013. (Photo by Ali Abu-Salah/Reuters/Shaam News Network via The Atlantic)

Children, some in tears, are escorted down a road in Barcelona, Spain, Thursday, August 17, 2017. Police in Barcelona say a white van has mounted a sidewalk, struck several people in the city's Las Ramblas district. (Photo by Manu Fernandez/AP Photo)

Street fighting in Berlin between Government troops and Spartacists, during the Spartacist uprising which followed Germany's defeat in World War I. (Photo by Keystone/Getty Images). 1919

A model poses at Checkpoint Charlie, a historic place in the German capital to promote the fashion magazine “Sous” on June 12, 2012. (Photo by Maurizio Gambarini)

Syrians try to rescue a dead body under the debris of a collapsed building after Syrian and Russian army carried out an airstrike on opposition controlled residential area at Merce neighborhood of Aleppo, Syria on September 23, 2016. (Photo by Jawad al Rifai/Anadolu Agency/Getty Images)

West Berliners crowd in front of the Berlin Wall as they watch East German border guards demolish a section of the wall on November 11, 1989. (Photo by Gerard Malie/AFP Photo)