People hold a banner depecting Serbian President Aleksandar Vucic and Russian President Vladimir Putin in front of Belgrade's Saint Sava Church on January 17, 2019. - Russian President Vladimir Putin on January 17, 2019 called for stability in the Balkans during a pageantry-filled visit to Serbia, a key Moscow ally in a tense region on Europe's edge. Although Serbia and all of its neighbours aspire to join the European Union, Belgrade has nurtured close ties with Russia, its historical "Orthodox big brother" whose people also share Slavic origins. (Photo by ANDREJ ISAKOVIC / AFP)