I spent six months of my life in Sarajevo in 1997/8 as the UK military representative at the OHR - (Office of the High Representative) a UN position.
Kosovo was going on while I was there.
I was not at all impressed by the peace dividend that had allegedly been brokered, and spent most of my time trying to keep Serbs, Croats and Bosniaks at peace and talking to each other. I never thought that I was successful in my endeavours. They did not seem keen to get on with each other.
So I am not at all surprised that Serbia is possibly acting as a surrogate to Putin's current Ukraine adventure. Putin might enjoy a distraction west from what he seems to be up to in Ukraine, and Serbia would probably enjoy their efforts at regional domination as well.
The world is not as peaceful as it was during the Cold War.
Just my opinion.
Does anyone have an answer?