Serbian President Vucic resigns after call with Putin; Russian media links events

Serbian President Aleksandar Vucic has resigned, and Russian state media RIA Novosti suggests the timing with his phone call to Vladimir Putin is not coincidental. The resignation is confirmed, but the nature of the call and any causal link remain unclear. This matters because Serbia's balancing act between EU integration and Russia ties is a key geopolitical fault line in the Balkans.