that the admission of ukraine to nato — the north atlantic treaty organisation , could trigger world war three. meanwhile, turkey has been trying to act as a mediator in this war. buy does all of this lead the people of ukraine? could p still prevail miss with me in the studio is our security correspondent frank gardner, and orysia lutsevych, head of the ukraine forum at chatham house. and we'e are also delighted to welcome professor kata ryna wolczuk, from the university of birmingham's centre for russian, european and eurasian studies, drjustin bronk is a senior research fellow at the london based military think—tank rusi, he is an expert in airpower and technology, and from the bbc�*s russia service olga ivshina. we'll be hearing from each of our special panel in a few minutes, but first frank is going to set the tone for this discussion by reminding us of the key recent developments and statements — and what they might tell us