The Other Big Lessons That the U.S. Army Should Learn from Ukraine
warontherocks.com
warontherocks.com
I also wouldn't put it behind Russia to seriously test European unity. Would an attack of Estonia trigger nuclear war? Unlikely. A counter attack on Moscow certainly would. Russian leadership doesn't have that much to lose sadly.
Russian army has lost over 35000 men and over 4000 units of armored vehicles (tanks, AFV, IFV etc) and yet it keeps going while in the Western world any such loss would have considered catastrophic.