destruction across enormous areas. tactical nuclear weapons — are designed for use in battlefield situations at much closer range. they are smaller than strategic nuclear weapons but still they cause enormous destruction. experts say these would be more likely be used inside ukraine. there is a clear distinction between these two types of weapons, but not really any distinction on how the other side would consider their use. even the russians believe a nuclear strike, regardless of whether it was tactical or strategic ould be the start of a much greater nuclear conflagration. let's bring in pavel podvig, one of the world's leading experts on russian nuclear forces. lovely to have you on the program. what does that announcement that president putin made over the weekend, what does it change in terms of the command structure? we don't terms of the command structure? , don't know exactly, of course. but it does appear that it changes the