It seems to me that annexing Crimea counts as an invasion, so I'm not sure why the author thought Russia would not invade more. > It did not go any further in

It seems to me that annexing Crimea counts as an invasion, so I'm not sure why the author thought Russia would not invade more. > It did not go any further in trying to conquer Ukrainian territory. Yeah, they stopped there and got an idea of what the international community would do in response to the invasion. (Little, or at least not enough (as is now obvious)).