Ukraine has launched a new offensive in Russia’s region of Kursk. But it’s not clear why exactly Ukraine is waging a new assault in Kursk, and why now.

The surprise attack seeks to reverse Ukraine’s decreasing hold of the region. Since Kyiv’s forces gained partial control of Kursk following a daring cross-border assault last August, Russian troops, aided by North Korean soldiers, have halved the territory held by Ukraine, albeit while suffering thousands of casualties.