but russia is not giving up. neither side seems ready to negotiate. so could russia still defy the odds and win this war, or will ukraine prevail? 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 2 main battle tanks. if used cleverly, these could potentially punch right through russian lines. from europe, german—built leopard tanks have also arrived. and there's more armour on the way. the us is sending more than 30 of its m1 abrams tanks. russia for its part says, well, the arrival of these western tanks won't change anything. the kremlin spokesman was pretty dismissive about it. have a listen to this. well, ok, but that's far from certain, as these tanks are far better armoured than anything else on the battlefield. and then there is artillery. ukraine says it needs 350,000 shells a month just to hold back russian forces. the eu has now agreed agreed a 2 billion euro deal to supply a million shelves. kyiv calls this a game changer. and that's not all. throughout the winter, thousands of ukrainian soldiers have been trained up at nato bases all over europe. they're returning to the battlefield just as russia's own attempt at advance appears to be running out of steam. over the winter, russia suffered huge losses of men and materiel. so too did ukraine, but the russians only gained tiny amounts of territory. in vuhledar, for example, it lost dozens of tanks and armoured vehicles. around another objective, the city of bakhmut, the fighting has been drawn out and intense. the russians took huge casualties there and across that eastern front line. the bbc�*s quentin sommerville witnessed the fighting in the donbas right up close with the ukrainian army. this infantrymen is only 22 years old. he is escorting us forward. he has just told me the village over here is half held by the ukrainians and half held by the russians. explosion. artillery fire. that's two russian shells that have just come in. i think it's tank fire. the safest place for these men is in the trenches. and quentin sommerville is with us now. quentin, we got a flavour of it there in that clip. what is life like down at trench level? well, frank, it's very muddy and very dangerous. we've just moved from winter into spring, so there was this thick mud all over every battlefront that we went through. and in that particular set of trenches down in the south of donbas, the men have been dug in there for about seven months. and actually, as i was going through that area, they were digging the trenches deeper. and the reason they were doing that was because they're facing relentless russian fire every single day. and the russians are throwing everything at them, whether it's automatic grenade fire, artillery fire, tank fire, grads — everything is being fired at that particular unit. and they're saying that whereas they do respond, they can in no way match the kind of firepower that the russians have. does the artilleryman think russia could win here? translation: it's a good question. l this question does need to be addressed to the senior military. oh, that was close. later in that report, he said to me, the russians have warehouses full of these shells. and certainly russia has lost its capability in some of the most sophisticated weaponry, but when it comes to your traditional artillery shells and grenades sent from automatic grenade launchers, they've got plenty. whoa! you've spent a lot of time with ukrainian soldiers. how do you rate them as fighters? i think that one of the things they always tell you is they always fetishise nato standards. when you meet... there are different parts of the ukraine armed forces, and depending on the brigade you meet or the battalion you meet, some of them have had that nato training and they're very, very able, very capable, and they've learned the ways to operate in urban combat and in the trench warfare we've seen. for others, that isn't the case. they haven't had that training, particularly the volunteers. and because we've seen a significant attrition of ukrainian forces, and a lot of russians, of course, have died on the front lines, but a lot of ukrainians have died too. remember, ukraine is a far smaller country with far fewer reserves to draw upon. well, quentin, stay there if you can, please. general sir richard sherriff was the former deputy supreme allied commander of europe for nato and also, very importantly, he was the author of a book called war with russia which has turned out to be pretty prescient. general, let's cut to the chase, here. do you think russia could win this war? i don't, and i say that because the ukrainians will continue to fight, whatever happens. and ijust don't think the russians have got the capability, the means, to achieve the ends that putin has set for himself, and that aim is to destroy ukraine as a sovereign state, to incorporate it into the russian federation, to put a puppet government of some sort in kyiv and to rebuild a second russian empire. general, ukraine has for the large part in the last 13 months fought a defensive war, trying to fend off this invasion. how good do you think it can be at offensive operations, given that that is what it's going to take to dislodge the russians. well, the ukrainians have demonstrated pretty effectively in two very successful counteroffensives, north—east of kharkiv and the recapture of kherson in november. so they've got form here, they can do this. and of course, before that, they stopped the russians dead in the battle for kyiv and forced the russians to withdraw, so that was a really significant victory for them as well. the ukrainians have given us a masterclass in operational manoeuvre and campaign design, so providing they've got the tools to do the job, they can do it. is there a risk, do you think, general, that because ukraine has this great big long shopping list of the weapons that it needs, including long—range missiles and fighterjets, and it's not getting everything it wants from the west, is there a risk that failing to send those weapons will cost it a victory in this war? there is a real risk that as a result of failing to give the ukrainians the tools to do the job, this will become protracted, attritional conflict which will go on for a very long time. think the iran—iraq war of the 1980s as a sort of worst case attritional fight. and the message is clear. i think there is a clear equation here. the quicker ukraine gets the tools it needs to do the job, the quicker ukraine can achieve if not 100% of his military objectives at least enough of its military objectives to assure itself that it can be safe and moreover get that message firmly into putin's brain that he's not --oin to achieve his objectives and therefore he might as well stop fighting. and so, yes, there is a real imperative from the west to continue to provide and to really ramp up that supply of weapons and other military capability, and of course logistics, ammunition, and the rest of it. there is a risk, though, of escalation, isn't there? we had that clash over the black sea not that long ago where russian su—27 fighters essentially brought down a us surveillance drone. how worried are you about escalation? well, escalation is a risk, and it has to be taken very seriously indeed. we as nato, we as the west, should not take counsel of our fears here. and let's put it into perspective. i think any use of tactical nuclear weapon or whatever — i think the signals would be pretty clear fairly early on, and i'm pretty certain that western intelligence agencies, satellites and the like will be tracking very carefully any potential rollout of warheads, linking up of warheads with delivery vehicles and the like. and i'm sure, equally, that the warnings have been made very clear to the russians at different levels in the kremlin and elsewhere that any such use will attract really, really painful, significant consequences. and we don't need to... you don't need to tell them what the consequences could be in detail, but i think enough to signal. what about russia's ability to gear up its industry, to churn out relatively low—grade, low—quantity weaponry, but in vast numbers? is there a risk that the kind of strength and depth that russia has could eventually win this war for them? they are capable of pushing out vast numbers of expendable manpower, supported by huge quantities of artillery, but i'm not sure russia can continue to do that. and i think all the indications are that the winter offensives which, as you say, have been extraordinarily attritional, the sort of battles around bakhmut and the like, are casualties on a scale which would be recognisable by any veteran who had thought through the somme or passchendaele or verdun in the first world war, they appear to be culminating. and the more russia fires its expendable manpower against the ukrainians, yes, the ukrainians are suffering and, yes, they're taking heavy casualties, but i don't think the russians can continue indefinitely. to the lay observer, russian tactics don't seem to have evolved very much since the second world war — i mean, hammeran objective with loads of heavy artillery and eventually send infantry to crawl over the rubble. i think what we see is a soviet military machine which in a sense reflects the state that it serves, which is corrupt and pretty incompetent. but nevertheless, that incompetence bears a danger because as a result of that, they have fallen back on plan b — attrition, destruction of cities, massacre of civilians, genocide, deportation of children, use of mass rape. so it's still a machine to be feared and ultimately to be destroyed. alright, so we've examined the possible that ukraine could get the better of russia this summer, but what if that doesn't happen? what if things continue more or less as are now? well, a war of attrition, and that is what this is starting to look like, probably favours russia in the long run. the kremlin knows that western support for ukraine simply cannot be sustained indefinitely at these current levels, and it has the advantage when it comes to manpower. russia has far more troops than ukraine does, and in a long war, that could make all the difference. back during the second world war, for example, stalin used their superiority in numbers to great effect. back to the present day, russia's industry has been moving on a war footing, and president putin really doesn't have to worry about domestic opposition. if he were to declare victory, it is important that we define what that word might mean. at a minimum, it means holding onto what russia has already seized, so crimea and the four illegally annexed oblasts, or provinces, in the south and east of ukraine, although actually, russia still doesn't control all of those areas. even after an elaborate ceremony and ask though declaring them to be an eternal part of the russian federation. and yet, still the longer russia occupies even a part of them, the greater the chance that it will get to keep that territory in any eventual peace settlement. then, at the other end of the spectrum, the maximum definition of the russian victory would be their taking control of the whole of ukraine, including the capital kyiv, replacing president zelensky�*s government, seizing all those expensive western weapons and inflicting a massive humiliation in the west. so, if this war does wind up with the result anyone within those two boundaries, the minimum and maximum definitions, then russia could still declare it as a victory. so, does this mean that a long war inevitably plays into putin's favour? let's ask professor sam greene who is an expert on russia with kings college london. professor greene, let's dig into what victory means for both sides. for ukraine, it is fairly straight forward, it means restoration of territorial integrity, sovereignty, the absence of russian troops and ideally some idea ofjustice, restoration and retribution from russia, prosecution of war crimes and that sort of thing. a victory for putin is whatever allows him to maintain his power within russia. he has tremendous leverage with which to do that, obviously he controlled state television, which is the only television available to most russians, he controls all of the parties that are competitive in the political system, he controls most of the levers of government and economy, which means that he can spinjust about anything as a victory, at least for the population, and for large portions of the elite. so he can — if he decides tomorrow, he has got as far as he can reasonably get, he does have the possibility of stopping, and putting up a banner that says, mission accomplished. if this war grinds on into a stalemate which it has been a little bit looking like, a war of attrition, does that play into put in�*s favour? i think it does. one of the things that putin has told people and it seems to have worked in terms of his rhetoric genetically is that this is not a waragainst ukraine. a stalemate, a war of attrition against a much smaller and theoretically weaker country would be an embarrassing thing, but a war against a west that is hell—bent on the destruction of russia, right, a war that is existential to the survival of russian society, as putin has painted this, is one that really cna continue to motivate politics and motivate sacrifice from everybody in the system. for quite some time. in fact, if this were were to end tomorrow, and it would then become clearer that frankly there's not, you know, a whole lot more that can be fought for the moment. then putin is it in a different position, he has to explain what all the sacrifice was for. how key do you think china is russia's ability to eventually become victorious in this war, we still don't know if they are going to provide weapons or not, but they are certainly providing political and moralsupport, itappears, even though they say they are neutral. i think what china is certainly pivotal to is the survival of putin as a pledge of a project. the reality is that having decoupled himself from the west, he needs investment capital, he needs diplomatic cover internationally, he needs friends in the world with which he can do business but also, again, to send that signal to the russian population and russian elite that you are not alone in the world. yes, we have cut you off from europe but there are others out there and you can move in that direction. without china, all that falls apart. coming back to the idea of a russian victory, within those parameters that we described, the minimum being what they already have taken and the maximum being overthrowing zelensky because my government and taken over the country, what is your prognosis? putin did not expect to be fighting this long. if he had won the resounding victory he expected in the early days, that would have been an easy thing. right now, i think he may be coming to the conclusion that it's better to keep fighting, it's better to keep this war going on some level, may be a lower level, maybe grind it into low—level skirmishes along a fairly stable line of control in the future, but as long as he can maintain the active conflict, it keeps politics focused on him, it keeps him in a position where he can keep demanding sacrifices and receiving sacrifices from the rest of the system in ways which might be much more difficult to do if this war were actually to end. all right, so let's take a step back and look at the bigger global picture. where does the rest of the world stand this war? russia still has friends around the world like south africa, for example, where its navy has recently been holding joint war games along with a chinese navy. since then, putin has become a wanted war crime suspect with an arrest warrant issued by the international criminal court. that should give some countries. —— that should give some countries pause for thought. but even the united states is not a sure—fire bet for ukraine. under the biden administration, it has sent them over $40 million worth of military aid but if the republicans win the white house next year, they might well curtail that support. let's look a little closer at what the impact of the weaponry that's already arrived in ukraine could have. we'll hear more from our reporter quentin somerville, but first he is currently in a herd from the institute of the study of war. the arrival of tanks to the front line of ukraine is undoubtedly going to be a crucial part of the ukrainian military to launch counter operations in the coming months. however, it is important to remember that tanks, just like any other western provided system, is not necessarily a golden bullet and not necessarily the answer to all of ukraine's needs. so, the use of tanks to conduct effective mechanised manoeuvre warfare is incredibly important, but so is the continued support of the west, in terms of artillery supply and the supply of long—range precision weapons such as the himars systems. on that point, i think the kind of so far the level of cohesion western support as surprise a lot of people, not least president putin, i'm sure, but it can't last forever at this level. what happens if military support dries up, if, for example, the republicans get in, in the elections in the states, and they dial down how much they're sending, can ukraine still fight this war? the interesting part is we had seen the ability of the ukrainians to conduct incredibly effective lightning counteroffensives earlier on in the fall of 2022. so, we saw the kharkiv and kherson counteroffensives occur incredibly effectively, incrediby quickly, this was when the west was still very much keeping ukraine in a starvation diet in terms of weapons. —— in terms of aid. ukraine in a starvation diet in terms of aid. the goal should be that the west continues to provide ukraine with the systems they need. we know the ukrainian military has the ability to conduct counteroffensive without the systems. we are going to have a look at the map now and take a look at what an expected ukrainian counteroffensive would look like if they're going to advance. and you can see on the map there the red areas the russian and you can see on the map there the red areas the russian—controlled by the arrows showing what's expected, which is a push south from the still ukrainian controlled city of zaporizhzhia to try to split into the russian—controlled areas. —— split in two quentin, do you think ukraine has enough in reserve and will be ready to carry out that kind of successful manoeuvre? well, there are two things that we know about ukraine at the moment, we know that they are preparing brigades separately from all the other funds they are facing for that offensive. they are keeping back resources, keeping back men, training men. some of the men who have been trained overseas, some of the most accomplished soldiers will be involved in that offensive. the second thing, really, i would say is that the one thing for this war has taught me is that you can never underestimate the ability of ukraine to launch a surprise. no one really expected the kharkiv offensive. sadly the russians didn't, and it was hugely successful. there's been a lot of signalling about the zaporizhzhia offensive, it may well happen, there may be room for an offensive elsewhere. carolyn, you work for the institute for the study of war which has become a byword for incredibly accurate and detailed maps, over the last year the map hasn't changed that much from a distance, the russian advances have been very small and incremental so not really since khersonm, since the russian abandoned kherson have we seen much change. do you expect in the coming months and this year, the rest of this year the battle lines to change? i would say that we are entering the prime time for ukraine to regain the initiative and really take advantage of russian weaknesses. we've seen signalling on the part of ukrainian military command that this may be in the south. there are also opportunities in other locations, and donbas and donetsk and we do expect the battle lines to change because the russian offensive has largely culminated in multiple areas on the front which will allow ukraine the opportunity to exploit this culmination and pursue their own counteroffensive in a way that will fundamentally change the front line. so, this war could still go in different directions, including the ukraine victory, or a long drawn—out stalemate which would tend to work in russia's favour. there is an urgency here for ukraine, which is why it's pushing the west so hard for more weapons. it knows that if it can't score a decisive victory against russia this year, then it may well have lost its best chance to reverse this invasion. hello there. i hope you've been making the most of the easter sunshine because on sunday the weather starts to change with some wetter weather in time for easter monday. at the moment, we're in between high pressure and low pressure. that gives us a southerly wind. it's that weather front coming in from the atlantic that will signal the change. still dry overnight. and these are the temperatures by sunday morning. so not as cold as it has been of late. there may well be more cloud around for easter sunday, but we will see the sunshine coming through at times. it's in northern ireland, though, that through the afternoon the cloud will tend to thicken. some patchy rain coming in here over the irish sea by the end of the day as well. and ahead of that advancing rain, we'll have a stronger southerly wind. now that's going to bring us a bit of warmth. temperatures could reach 17 degrees around the murray firth, north wales, merseyside, perhaps london and the home counties, but a few degrees cooler than that in northern ireland with the rain arriving here and that band of rain will push its way into western parts of britain during the evening, continue eastwards overnight. heaviest rain over the hills in the west and followed by some bands of showers sweeping across northern ireland into southwest scotland. so with all that cloud and rain around, sunday night should be pretty mild into monday morning. easter monday though we still have that rain to clear away from eastern parts of england. it could linger throughout the morning in east anglia and the south east. following on from that, some sunshine. but these bands of showers could be heavy with some hail and thunder and there'll be some frequent showers across northern and western parts of scotland. we'll have a chillier breeze and temperatures are going to be lower. we're back down to around 10 to iii degrees in the afternoon. we're into that showery air stream as we head into tuesday. but this developing area of low pressure is going to be heading our way as well. whilst many places could start the day dry with some sunshine, we've got showers in northern scotland. we'll see the cloud increasing, the wind picking up from the south—west, and rain moving its way northwards and eastwards through the day. and tuesday could turn out to be quite chilly, actually. temperatures typically 10 to 13 degrees. a lot of uncertainty overnight and into wednesday. the models are differing with the depth of that area of low pressure and the position. but for a while actually, it could be quite windy across some parts of the country and that signals this change to more unsettled weather over the week ahead. showers or longer spells of rain and temperatures by day on the low side for this time of the year. live from washington, this is bbc news. hundreds of palestinians have barricaded themselves inside al—aqsa mosque injerusalem. girls at schools across iran are taken to hospital after another outbreak of apparent gas poisoning. and we'll find out why hawaii is considering a tax on tourists. hello, i'm carl nasman. we're getting in some more news from israel. hundreds of palestinians have barricaded themselves inside al—aqsa mosque injerusalem. remember, earlier this week israeli police raided the mosque after palestinians barricaded themselves inside after the evening ramadan prayer.