German field telegraph operators at work in Warsaw. (Photo by Hulton Archive/Getty Images). 1st October 1914

Cars pass a tank position close to the Russian border near the Ukrainian city of Kharkiv March 24, 2014. U.S. President Barack Obama sought support from European allies and China on Monday to isolate Russia over its seizure of Crimea, and Ukraine told its remaining troops to leave the region after Russian forces overran one of Kiev's last bases there. (Photo by Dmitry Neymyrok/Reuters)

NATO and U.S. flags flutter as U.S. Air Force F-22 Raptor fighter flies over the military air base in Siauliai, Lithuania, April 27, 2016. (Photo by Ints Kalnins/Reuters)

A Ukrainian serviceman takes a rest near the town of Bakhmut, in the Donetsk region on April 28, 2023, amid the Russian invasion on Ukraine. (Photo by Dimitar Dilkoff/AFP Photo)

An Ukrainian serviceman caresses a cat near Bachmut, on March 23, 2023, amid the Russian invasion of Ukraine. (Photo by Aris Messinis/AFP Photo)

Military chaplain Yurii looks on in a trench after an Orthodox Easter service for Ukrainian servicemen at their position, as Russia's attack on Ukraine continues, in Kharkiv region, Ukraine on April 15, 2023. (Photo by Sofiia Gatilova/Reuters)

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

People in historical uniforms prepare for a parade at Red Square commemorating the 75th anniversary of the Red Army’s defence of Moscow during the second world war in Moscow, Russia on November 7, 2016. (Photo by Stanislav Krasilnikov/TASS)