As Ukraine’s Kursk incursion forges on the stakes are rising for both sides

Kyiv's push into Russia has psychological and political advantages, but it knows Putin cannot let it lie

• Russia-Ukraine war - latest news updates

Nine days into Ukraine's incursion into Russia, and Kyiv is showing increasing confidence. Two soldiers, speaking off the record by a dusty roadside a few miles from the border, said they expected logistics functions to be brought forward inside Russia" because supply lines were becoming stretched.

Though it is a fragmentary detail - being more specific would endanger life - it demonstrates that as Ukraine's forces continue to advance into Kursk oblast, Kyiv is gradually becoming more committed to an incursion that may have begun brightly, but the eventual outcome of which remains profoundly uncertain.