Russian forces gained territory in August and September at a pace not seen since 2022.

Inside the Kremlin, there is a growing recognition that the repeated use of the nuclear threat is starting to lose its potency.

Ukraine launched its daring incursion into Kursk in August, partly in the hopes Russia would divert troops there from Donetsk in eastern Ukraine where a push by the Russian army is threatening to overrun a belt of key defensive strongholds.

Ukrainians argue that being empowered to use the weaponry against Russian territory would reduce the threat from Russia by forcing it to pull key forces deeper inside its country.