Day 258.Today, we discuss the brutal fighting in the centre of Ukraine; analyse the emergence from the shadows of Yevgeny Prigozhin and his mercenary army, the Wagner group; and Dom Nicholls takes us through the principles of a good defence as the Russian army digs-in, in the South. Contributors: David Knowles (Host). Follow David on Twitter @DjKnowles22.Dom Nicholls (Associate Editor, Defence). Follow Dom on Twitter @DomNicholls.Francis Dearnley (Assistant Comment Editor). Follow Francis on Twitter @FrancisDearnley.James Kilner (Foreign Correspondent). Follow James on Twitter @jkjourno.Email: podcasts@telegraph.co.ukSee Privacy Policy at https://art19.com/privacy and California Privacy Notice at https://art19.com/privacy#do-not-sell-my-info.