A shake-up and breakthrough? Ukraine's counteroffensive at crossroads

Ukraine is facing a critical moment both on and off the battlefield.

Its troops are fighting to turn what appears to be a minor breakthrough in the south into a substantial breach of Russian lines before winter sets in. And in Kyiv, the defense minister has been dismissed in the biggest shake-up of the country’s leadership since the war began.

The departure of Oleksiy Reznikov has been rumored for months and appears linked to a broader anti-corruption drive, but the timing coincides with developments in another effort that could be crucial to securing ongoing Western support: The first claims of potentially significant gains in the military’s counteroffensive.

Ukrainian forces are gaining a foothold in the area where they have breached Russia’s first main defensive line in the south, Yuriy Sak, an adviser to Ukraine’s defense minister, told NBC News on Monday.

“Everything is very dynamic” right now, but the initiative is “definitely on our side,” Sak said on the phone from Kyiv.