(Intro) As the world marked a tragic milestone on Saturday, we should remind ourselves that Ukraine's progress as a full-fledged democracy shook the seat of power in Moscow to its core, Aleksandar Đokić writes: On Saturday, the world marked a tragic milestone: the 500th day of Russia's full-scale invasion of Ukraine, an all-out escalation of the Kremlin's war against Ukraine that has been taking place since 2014, when Moscow troops first entered Crimea and then the Donbas regions of Donetsk and Luhansk. Even after all this time, some Europeans still struggle to understand the reasons for Vladimir Putin's act of...