Ukraine invasion: As the fight moves into its fifth day - why are Putin's forces making such slow progress?

Professor Michael Clarke, former director general of the Royal United Services Institute (RUSI) and a security analyst, offers his assessment of the current situation. "This is the first time the Russians have employed a combined arms operation since 1979, with everything since being alongside special forces, elite forces and Russian mercenaries working with locals - and those were ruthless and brutal. This full scale offensive in Ukraine isn't something they are used to...."