in this programme, we're going to examine how either side could yet win in ukraine. more than a year after the invasion began, the fighting has reached another inflection point. ukraine has the initiative. they're expected to launch a new offensive during the spring and summer. but if they don't make decisive gains quickly, that could put russia in the stronger position, because the longer this war drags on, the greater the odds of an eventual russian victory. let's look first at what has put ukraine once more on the front foot. modern, powerful western tanks have now started arriving in ukraine, and they'll be heading to the front. thank you very much from ukraine, united kingdom. from the uk, challenger