According to [0] the military was basically doing under-the-radar preparations in the last few weeks before the attack, because the official narrative was that nothing's gonna happen.
> A small group of officers at HUR, Ukraine’s military intelligence agency, did begin quiet contingency planning in January, prompted by the US warnings and the agency’s own information, one HUR general recalled. Under the guise of a month-long training exercise, they rented several safe houses around Kyiv and took out large supplies of cash. After a month, in mid-February, the war had not yet started, so the “training” was prolonged for another month.
> The army commander-in-chief, Valerii Zaluzhnyi, was frustrated that Zelenskyy did not want to introduce martial law, which would have allowed him to reposition troops and prepare battle plans. “You’re about to fight Mike Tyson and the only fight you’ve had before is a pillow fight with your little brother. It’s a one-in-a-million chance and you need to be prepared,” he said.
> Without official sanction, Zaluzhnyi did what little planning he could. In mid-January, he and his wife moved from their ground-floor apartment into his official quarters inside the general staff compound, for security reasons and so he could work longer hours. In February, another general recalled, table-top exercises were held among the army’s top commanders to plan for various invasion scenarios. These included an attack on Kyiv and even one situation that was worse than what eventually transpired, in which the Russians seized a corridor along Ukraine’s western border to stop supplies coming in from allies. But without sanction from the top, these plans remained on paper only; any big movement of troops would be illegal and hard to disguise.
[0] https://www.theguardian.com/world/ng-interactive/2026/feb/20...