NATO allies send jets, ships to enhance Eastern Europe defences

The analysis of combat tactics is that time may be running out if Russia intends to attack Ukraine. Cold winter conditions make hard ground ideal for tanks, but once spring approaches, the land can turn to mud, making it more difficult to move military hardware. The same time constraints also apply to the west, which is trying to deter a possible invasion through diplomacy with Moscow, the threat of sanctions, and sending lethal assistance to Ukraine. Our Europe correspondent, Simon McGregor-Wood reports.