A Syrian Democratic Forces (SDF) female fighter adjusts a mortar in northern Deir al-Zor province ahead of an offensive against Islamic State militants, Syria February 21, 2017. (Photo by Rodi Said/Reuters)

A fighter belonging to Jaish al-Islam (Islam Army) runs to take cover near the frontline on March 14, 2016 in the neighbourhood of Jobar, on the eastern outskirts of the capital Damascus. (Photo by Amer Almohibany/AFP Photo)

A Russian ground staff member signals to the pilot of a Sukhoi Su-25 fighter jet at the Hmeymim air base near Latakia, Syria, in this handout photograph released by Russia's Defence Ministry October 22, 2015. (Photo by Reuters/Ministry of Defence of the Russian Federation)

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

Internally displaced Syrians who fled Raqqa tie ropes for their tents in a camp in Manbij, Syria on April 6, 2017. (Photo by Rodi Said/Reuters)

In this photo made Thursday, April 11, 2013, Soviet Jewish World War Two veteran Boris Ginsburg poses for a portrait at his house in the southern Israeli city of Ashdod. Ginsburg, born in Belorussia, was kept by a German garrison in the Lenin ghetto since 1941 until its destruction by partisan units in September 1942. In 1942 he joined the partisans for two years and in 1944 he joined the Red Army as a combat soldier and fought till the and of the war. Ginsubrg demobilized in 1947 and immigrated to Israel in 2001. About 500,000 Soviet Jews served in the Red Army during World War Two, and the majority of those still alive today live in Israel. (Photo by Oded Balilty/AP Photo)

Syrian government troops patrol the newly captured al- Sakhour neighbourhood in the eastern part of the northern city of Aleppo on December 7, 2016 Rebels in Aleppo called for a five- day truce and the evacuation of civilians Wednesday after losing more than three quarters of their territory including the Old City to a Syrian army offensive. (Photo by George Ourfalian/AFP Photo)