A Russian trenchmortar crew run to take up a new firing position in the Stalingrad area during the Great Patriotic War. (Photo by Keystone/Getty Images). October 1942

Ruins of a building are seen in the old village of Belchite, in northern Spain, November 13, 2016. Almost 80 years ago Tomas Ortin fled under the cover of night from his home in the small town of Belchite on Spain's northern plains to escape with hundreds of others from one of the bloodiest battles of the country's civil war. At 94 years old, Ortin now lives just across the road from Belchite, which has lain in ruins since Republican forces attacked it, a symbol of the destruction caused by the 1936-1939 war in which an estimated 500,000 people died. (Photo by Andrea Comas/Reuters)

Reenactors playing the roll of Kentucky volunteers, fighting for the United States, fire muskets during a reenactment of the Battle of New Orleans in the War of 1812, marking its bicentennial in Chalmette, Louisiana, January 10, 2015. The participants, some of whom have travelled thousands of miles to join in the event, recreated the five clashes that comprise the battle, which some historians say was key in making the British honor the terms of a peace treaty signed in late 1814. (Photo by Lee Celano/Reuters)

Rebel fighters from the Ahrar al-Sham Islamic Movement fire a heavy machine gun during what they said was an offensive to take the northwestern city of Idlib March 24, 2015. (Photo by Khalil Ashawi/Reuters)

Newly-wed Syrian couple Nada Merhi, 18, and Hassan Youssef, 27, have their wedding pictures taken in front of a heavily damaged building in the war ravaged city of Homs on February 5, 2016. A Syrian photographer thought of using the destruction of Homs to take pictures of newly wed couples to show that life is stronger than death. (Photo by Joseph Eid/AFP Photo)

A young woman employee of North American Aviation Incorporated, working over the landing gear mechanism of a P-51 fighter plane, Inglewood, California, 1942. (Photo by Alfred T. Palmer/Buyenlarge/Getty Images)

An Israeli tank moves into position in the Israeli controlled Golan Heights during fighting between forces loyal to Syrian President Bashar Assad and rebels in the Druze village of Khader in Syria, Tuesday, June 16, 2015. As many as 20 members of the Druze minority sect were killed last week, the deadliest violence against the Druze since Syria's conflict started in March 2011, sparking fears of a massacre against the sect. (AP Photo/Ariel Schalit)

Wang Zeyu, 4, a fee-paying enthusiast of kung fu, practises during a training class at a kung fu school near the Shaolin Temple April 10, 2005 in Dengfeng, Henan Province, China. Zeyu's father sent him to the school from his home in Jiangsu Province, thousands kilometres away from Dengfeng, when he was just 3 years old. And his father must pay 9,800 yuan (US$1195) for one year's tuition at the school, a huge amount for most Chinese. There are more than 80 kung fu schools that line the road from the city of Dengfeng to the Shaolin Temple with hundreds and thousands of young kung-fu lovers from all over the country and beyond studying here. All the schools use the Shaolin name to attract students as the Shaolin Temple is the birthplace of Chinese Kung Fu. (Photo by Cancan Chu/Getty Images)