Thread by @shashj

Western official, asked abut Gerasimov's status: "whether he is in post or not, we haven't seen any significant change...in how the battle is taking place. The Russians continue to make seemingly the same tactical errors in how they are approaching the fight."

Western official, asked whether war is a stalemate, essentially says not yet: "if it continues like this then we can see it ending up as a stalemate...if we are still in this position come September, I think that's a reasonable description...overall the battle is finely balanced"

Western official: "Ukrainian personnel are highly motivated, highly experienced & in sufficient numbers to hold a defensive line but perhaps don't have the capabilities they might need". Russians taking heavy losses but "significantly overmatch Ukrainians in terms of capability."

Western official: "in terms of the battle for the Donbas, the ability for Ukrainians to manoeuvre is limited. They've been in well-fortified defensive positions for over eight years...large scale manoeuvre...would expose Ukrainians as much as it exposed...the Russians."

Western official, warning about limits of Ukrainian counter-offensives: "Their ability...to conduct large-scale manoeuvre and to significantly take the fight to Russians, pushing them out of entire regions, oblasts, I think remains limited at the moment."

Western official: "modern doctrine" says Russia should be moving 40km a day. "These gains which are being made are one or two kilometres at a time. And then the Ukrainians have been very effective at launching counter offensives" [i.e. on smaller scale]

Correction, this was "Russian doctrine", not "modern doctrine". It's also been pointed out to me that historical rates of opposed advance are actually way lower than this, per @JominiW below:

https://twitter.com/shashj/status/1525120569619927041?s=20&t=N35C8tnecXSgMoH-vNSJEA