A billboard at the main entrance to the city of Kupiansk illustrates the tenuous nature of Ukrainian control in a region that has become one of the most active parts of the 1,200 km front line in the war.
"Kupiansk is Ukraine!!!” it proclaims to anyone entering the city. The other side of the sign, visible to those in the city center, hints at why the first proclamation is so urgent. It shows an armed soldier standing in front of a helicopter, along with a phone number and a question: "Do you have information about traitors to Ukraine?”
At the outset of the war, Kupiansk, only 40 km from the Russian border, fell to Moscow’s forces without a fight and remained under occupation for six months before being retaken in a lightning Ukrainian thrust in the Kharkiv region in the country’s northeast in September.