[Goose]

My question is how close to Melitopol do they have to get?  Does Tokmak do it?  I know the real answer is it depends and the closer they get the more they will be able to shut down supply.  But what is the realistic answer to start to put big pressure on supply lines?  They are probably 1/3 of the way to Tokmak.....

There are at least two main problems with the offensive in Zaporizhzhia. The first one is the one you cite. How far does Ukraine have to go? IMO Tokmak won't do it. When Ukraine gets that far, it notionally can reach parts of the M14 and the railroad with artillery fire. The distance by from Tokmak to Melitopl' as the crow flies is  52 km (32 miles). The only "artillery" Ukraine has that can reach that far is the HIMARS/M270 systems. They don't need ATACMS at that range, which is good. The problem is that Ukraine has shown it is very difficult to interdict a road/railroad with HIMARS. These weapons generally create mass destruction when fired in quantity.  They aren't "sniper" type weapons. Ukraine also doesn't want to have a HIMARs sitting in a fixed location waiting for a Russian semi to come down the M14. The HIMARS needs to "shoot and scoot".

In theory it would be possible to "take a bit more ground" (like another 25 km) and set up an M777 "park". The "conventional" artillery can deliver a persistence of fires that the HIMARS cannot. The problem is that "park" would be in a fixed location outside any town. Even if you dig it in, it is a fixed target in the open. It wouldn't last long. Even the Russians can bomb that type of a position into oblivion :-). The position at Tokmat would allow periodic disruption of the "land bridge", which is a significant plus. Russia couldn't depend on everything they ship on the railroad/on the M14 reaching it's destination. However, it wouldn't close down the land bridge. Ukraine needs to "shut" that door. IMO Ukraine has to force the Russians to evacuate Melitopl' and occupy it themselves. Nothing less closes the land bridge emphatically. The Ukrainians themselves want to go all the way to Berdiansk. That probably isn't "necessary", as there are no major routes from Berdiansk directly to Crimea/Kherson Oblast.

Reaching Melitopol' isn't as far-fetched as it seems. The defenses Ukraine is fighting against in the south become progressively thinner the further they go. The Ukrainians now need to break the Russian "second line". They aren't doing too much right now. Hopefully they are re-organizing and preparing for the next phase. We know Russia has sent lots of troops that were stationed in Melitopol' (and nearby) toward the front. This is significant in two ways. First, the Russians seem to think they will be needed on the second line, and that they have no other source of troops available. They are being forced to "thin out" their defense in depth. Second, the Russians are also removing administrative troops from Melitopol'. They have also wired the bridges in the city for destruction.  This, coupled with sending troops from Melitopol' indicates IMO Russia does not intend to seriously defend the city. It makes sense. If Ukraine  gets that far, they can cut the railroad and the M14 at the city limits. Supplying Melitopol' at that point would become very difficult for Russia. 

The second major problem for Ukraine in this offensive is the "width" of their penetration. The last thing Ukraine wants is a salient "70 km long and 2 km wide". While they aren't quite that narrow, they are undoubtedly concerned that they are far too narrow. They also have to defend the flanks of their advance, and the further they go, the longer their flanks. It is probable they don't have the troops, and that is what is making them real nervous. The "theory" is that once you "break through", you widen the breach by quickly getting behind the defenses on either side of the breach and cutting them off. Ukraine probably wants to breach the second line before they do that. Ukraine's problem is that there aren't roads that run along the rear of the Russian positions. The terrain is open, and moving cross-country exposes Ukraine to air attack against which they have no really effective defense. What amazes me is that it appears that nobody in Ukraine or NATO seems to have thought this through and realized there was a "hole" in the strategy. Or, maybe they did but figured they had no other choices.

Ukraine may be able to widen the breach by moving at night and "hugging" the Russian defensive rear. A lot of this depends on how the Russians react to having Ukrainians behind them. Supply issues immediately come to mind. If the Russian troops don't "hold tight", it may work. It also may be Russian air is inefficient enough that Ukraine can tolerate it's presence. It would definitely be easier to do that than execute a frontal attack all along the Russian first line of defense. In any case, Ukraine needs a shorter front, not a longer one. Clearing Kherson Oblast will do that, but obviously that is an equally big job as taking Melitopol'. That is why the Ukrainian's pause in front of Kherson city in 2022 was so damaging. 

Undoubtedly Ukraine felt they didn't have the combat power to do otherwise, but the hope was they could keep pushing the Russians south. The fact they couldn't greatly helped to create this "front stretching" problem with the Zaporizhzhia salient. I had originally felt that the south Kherson Oblast should have been Ukraine's next place of offensive operations. Zaporizhzhia Oblast does bring several advantages however. One of them is a physically shorter distance to travel to break the land bridge. The other is the terrain is slightly better for the attackers. The discussions by Ukrainian infantry there is advancing "tree line to tree line". In south Kherson Oblast, there are more areas with no "tree lines" for miles. However, Zaporizhzhia has the disadvantage of Russians on both flanks with relatively good lines of supply. Kherson Oblast has the advantage the Russians are "only" in front of and on the Ukrainian left. However, Ukraine would have to go much farther to break the land bridge, and the break at that point would not be effective against Zaporizhzhia Oblast.

So yes, there are problems. Big ones. However, Russia has it's problems too. Neither side has a "way ahead" that is clear. Ukraine has accomplished a lot with relatively little. We can only hope that continues.

[Goose]

My question is how close to Melitopol do they have to get?  Does Tokmak do it?  I know the real answer is it depends and the closer they get the more they will be able to shut down supply.  But what is the realistic answer to start to put big pressure on supply lines?  They are probably 1/3 of the way to Tokmak.....

There are at least two main problems with the offensive in Zaporizhzhia. The first one is the one you cite. How far does Ukraine have to go? IMO Tokmak won't do it. When Ukraine gets that far, it notionally can reach parts of the M14 and the railroad with artillery fire. The distance by from Tokmak to Melitopl' as the crow flies is  52 km (32 miles). The only "artillery" Ukraine has that can reach that far is the HIMARS/M270 systems. They don't need ATACMS at that range, which is good. The problem is that Ukraine has shown it is very difficult to interdict a road/railroad with HIMARS. These weapons generally create mass destruction when fired in quantity.  They aren't "sniper" type weapons. Ukraine also doesn't want to have a HIMARs sitting in a fixed location waiting for a Russian semi to come down the M14. The HIMARS needs to "shoot and scoot".

In theory it would be possible to "take a bit more ground" (like another 25 km) and set up an M777 "park". The "conventional" artillery can deliver a persistence of fires that the HIMARS cannot. The problem is that "park" would be in a fixed location outside any town. Even if you dig it in, it is a fixed target in the open. It wouldn't last long. Even the Russians can bomb that type of a position into oblivion :-). The position at Tokmat would allow periodic disruption of the "land bridge", which is a significant plus. Russia couldn't depend on everything they ship on the railroad/on the M14 reaching it's destination. However, it wouldn't close down the land bridge. Ukraine needs to "shut" that door. IMO Ukraine has to force the Russians to evacuate Melitopl' and occupy it themselves. Nothing less closes the land bridge emphatically. The Ukrainians themselves want to go all the way to Berdiansk. That probably isn't "necessary", as there are no major routes from Berdiansk directly to Crimea/Kherson Oblast.

Reaching Melitopol' isn't as far-fetched as it seems. The defenses Ukraine is fighting against in the south become progressively thinner the further they go. The Ukrainians now need to break the Russian "second line". They aren't doing too much right now. Hopefully they are re-organizing and preparing for the next phase. We know Russia has sent lots of troops that were stationed in Melitopol' (and nearby) toward the front. This is significant in two ways. First, the Russians seem to think they will be needed on the second line, and that they have no other source of troops available. They are being forced to "thin out" their defense in depth. Second, the Russians are also removing administrative troops from Melitopol'. They have also wired the bridges in the city for destruction.  This, coupled with sending troops from Melitopol' indicates IMO Russia does not intend to seriously defend the city. It makes sense. If Ukraine  gets that far, they can cut the railroad and the M14 at the city limits. Supplying Melitopol' at that point would become very difficult for Russia. 

The second major problem for Ukraine in this offensive is the "width" of their penetration. The last thing Ukraine wants is a salient "70 km long and 2 km wide". While they aren't quite that narrow, they are undoubtedly concerned that they are far too narrow. They also have to defend the flanks of their advance, and the further they go, the longer their flanks. It is probable they don't have the troops, and that is what is making them real nervous. The "theory" is that once you "break through", you widen the breach by quickly getting behind the defenses on either side of the breach and cutting them off. Ukraine probably wants to breach the second line before they do that. Ukraine's problem is that there aren't roads that run along the rear of the Russian positions. The terrain is open, and moving cross-country exposes Ukraine to air attack against which they have no really effective defense. What amazes me is that it appears that nobody in Ukraine or NATO seems to have thought this through and realized there was a "hole" in the strategy. Or, maybe they did but figured they had no other choices.

Ukraine may be able to widen the breach by moving at night and "hugging" the Russian defensive rear. A lot of this depends on how the Russians react to having Ukrainians behind them. Supply issues immediately come to mind. If the Russian troops don't "hold tight", it may work. It also may be Russian air is inefficient enough that Ukraine can tolerate it's presence. It would definitely be easier to do that than execute a frontal attack all along the Russian first line of defense. In any case, Ukraine needs a shorter front, not a longer one. Clearing Kherson Oblast will do that, but obviously that is an equally big job as taking Melitopol'. That is why the Ukrainian's pause in front of Kherson city in 2022 was so damaging. 

Undoubtedly Ukraine felt they didn't have the combat power to do otherwise, but the hope was they could keep pushing the Russians south. The fact they couldn't greatly helped to create this "front stretching" problem with the Zaporizhzhia salient. I had originally felt that the south Kherson Oblast should have been Ukraine's next place of offensive operations. Zaporizhzhia Oblast does bring several advantages however. One of them is a physically shorter distance to travel to break the land bridge. The other is the terrain is slightly better for the attackers. The discussions by Ukrainian infantry there is advancing "tree line to tree line". In south Kherson Oblast, there are more areas with no "tree lines" for miles. However, Zaporizhzhia has the disadvantage of Russians on both flanks with relatively good lines of supply. Kherson Oblast has the advantage the Russians are "only" in front of and on the Ukrainian left. However, Ukraine would have to go much farther to break the land bridge, and the break at that point would not be effective against Zaporizhzhia Oblast.

So yes, there are problems. Big ones. However, Russia has it's problems too. Neither side has a "way ahead" that is clear. Ukraine has accomplished a lot with relatively little. We can only hope that continues.