Through out the history of war there are times when the 'offensive' weapons have the advantage and other times when 'defensive' weapons are superior. You only have to think back to the First World War when the machine gun and barbed wire ruled the battlefield until the tank appeared which, together with improved communications, resulted in Hague's Hundred days of victory in 1918. Is the tank now as obsolete as battleships where in the Second World War? The UK/Swedish New Light Anti Tank Weapon (NLAW) would suggest it might just do for the tank what the torpedo did for the battleship.
This is after all a weapon which any idiot can be taught to use in half an hour and only cost £30,000. Aimed in the general direction of a modern tank costing some £4.0 million it is curtains for the tank and the highly trained crew. Frankly having seen what the NLAW and the US Javelin anti tank weapon does to a tank I am not surprised that the Russian attack has stalled. Russian tactics have, ever since 1943, revolved round the tank being the Queen of the Battlefield -just as in medieval times the heavily mounted and armoured knight was until they came up against the Long bow.
So if tanks and armoured personnel carriers (APC) no longer give troops protection but instead are little more than mobile steel coffins how on earth are you going to move in and capture a city like Kiev? The short answer would be use PBI (Poor Bloody Infantry) to clear the buildings - well yes but the casualties are likely to be heavy so I am putting my money on a prolonged siege of the cities. The Russian army sitting back encircling them and hoping to starve them into submission.
Again I have my doubts about this tactic. I don't think time is on Putin's side. He needs a quick victory.