“How did you go bankrupt?” Bill asked. “Two ways,” Mike said. “Gradually and then suddenly.” That's from Ernest Hemingway, in his 1926 breakthrough novel, The Sun Also Rises.
I think that this quote is what is going to happen to the Russian Army in Ukraine. The lightening advance last September in Kharkiv is a forecast of what will happen next. The only question is when and where the Ukrainian army will break through and the Russians collapse.