Children play in an outdoor shower as a soldier takes part in a surprise operation in the Manguinhos slum in Rio de Janeiro, Brazil, Thursday, January 18, 2018. Troops have been sent to Rio due to the increase of the violence, and in an attempt to help restore order, but so far have had little impact. The operation on Thursday took place three weeks ahead of Carnival, when thousands of tourists are expected to arrive in the city. (Photo by Leo Correa/AP Photo)

Masked Palestinian demonstrators hide behind a metal plate during clashes with Israeli soldiers on March 12, 2018 in the West Bank town of Birzeit, near Ramallah, following a protest by students of the Birzeit University against the arrest of the the head of Palestinian student council by an Israeli undercover commando. (Photo by Abbas Momani/AFP Photo)

British troops arriving in England on June 6, 1940 after fleeing Flanders received all kinds of fruit and food from women who passed it out to them as they halted in railroad stations. A soldier holds aloft a banana he received from the woman. (Photo by AP Photo)

A World War II re-enactor dressed as Red Army soldiers rests after a staged battle to mark the liberation of the city of Ostrava by Red Army from the Nazi invaders in 1945, Czech Republic, Thursday, April 30, 2015. (Photo by Sergei Grits/AP Photo)

Indonesian Air Force soldiers from the Paskhas corps shout slogans during a rehearsal for a ceremony marking the 70th anniversary of Indonesia's military in Cilegon, Banten province, October 3, 2015. Indonesia will celebrate the anniversay of its military on October 5. (Photo by Reuters/Beawiharta)

A history enthusiast, dressed as a soldier, fights during the re-enactment of Napoleon's famous battle of Austerlitz near the southern Moravian town of Slavkov u Brna December 5, 2015. Hundreds of history enthusiasts gathered near the city of Slavkov before a re-enactment of Napoleon's famous battle of Austerlitz on Saturday to mark its 210th anniversary. (Photo by David W. Cerny/Reuters)

Soldiers of China's People's Liberation Army (PLA) jump as part of their winter training in temperature of negative 26 degrees Celsius at China's border with Russia in Heihe, Heilongjiang province, December 14, 2015. (Photo by Reuters/Stringer)

U.S. Army soldiers with the 1st Battalion, 501st Infantry Regiment deployed to Combat Outpost Sabari, Afghanistan scan their area as they begin a multi-day air assault mission near the Pakistani border of eastern Afghanistan's Khost province May 2, 2012. (Photo by Staff Sgt. Joshua L. DeMotts/U.S. Air Force)