I can imagine this could have been the motivation 18 months ago.

"In the early morning hours of 29 December 2023, Russia launched what was seen to be the largest wave of missiles and drones yet seen in the Russo-Ukrainian War, with hundreds of missiles and drones hitting the Ukrainian capital Kyiv and other cities across the country."

You have to wonder how much of that time was inventing/creating the actual capability on top of planning/rehearsing. Would be an interesting story in the mold of the "Dam Busters".