Ukraine forces have made only modest gains since launching their counteroffensive in June. In recent weeks, however, Kyiv said its military had breached Russia's first defensive line and liberated the village of Robotyne east of the Dnieper River. Retired US general and former CIA chief David Petraeus, who commanded US and allied troops in Iraq and Afghanistan, told DW's Anna Pshemyska there are reasons to expect Ukrainian forces to make further progress. But he also noted that Russia has been learning from its mistakes. 

DW: General Petraeus, do you share the assessment that there is a 50% chance that Ukrainians will breach the second and the third line of Russian defenses by the end of this year?

I think there's quite a good chance of that, but let me explain what has transpired over the first three months of the counteroffensive. 

What has been established here is what's true always — and I learned many times in my own career as a combat commander in two different wars — is that no plan survives contact with the enemy. But the question then is how well do the forces adapt. How well do they respond when you have to change the plan. I think the Ukrainians have done a very impressive job in that regard.

They have adapted what they were trying to do when they learned of the enormous depth of these Russian minefields. These are vastly deeper — we're talking kilometers, many kilometers in length, far deeper than the doctrinal distances in the Russian manuals. And the Ukrainians have had to pick their way through these because they don't have the air power, they don't have the armored breaching capabilities and so forth that we [the US] would employ for such a formidable defense.

So, the Ukrainian counteroffensive has obviously been very, very hard.

And so the Ukrainians have had to adapt. They have now begun to accumulate gains, particularly in the central Zaporizhzhya area around Robotyne and so forth. I think there's quite a good chance that they can continue this progress.

They're through the first defensive belt, they're into the second belt, if you will, keeping in mind that each of these includes tank ditches, very deep minefields, other obstacles, dragon teeth and so forth… trench lines full of Russian soldiers and on top of all of this are drones that are identifying the Ukrainian soldiers and then bringing in artillery and rocket fire on them.

So this is a very, very challenging task. It's beyond anything that I can recall seeing, really since the end of World War II. It's certainly vastly more challenging than what we saw in the two wars that I was privileged to command.

The question in my mind really is, when might the Russians begin to crack? When might this defense really begin to crumble? And then can the Ukrainians exploit that to take this at least as far as the distance that's required for the Ukrainians to be able to range that very important line of communication that runs from Russia along the southeast coast of Ukraine?

If they can interdict that and disrupt or even degrade the logistical capacity of the Russians to support their forces in the center part of the south of Ukraine, that would be quite a substantial achievement.

It is now said that the Ukrainian counteroffensive is slowly gaining momentum and that the breach near Robotyne is widening. So there have been some recent successes. What made them possible?

What made it possible is the Ukrainians adapting [...] And they're using essentially 10-man teams, small infantry squads and platoons fighting from tree line to tree line, picking their way through these minefields, establishing routes through them, then defending what they take. Then, a day or so later, taking the next tree line, the next house.

They've done this with enormous scale, tremendous courage, a lot of innovation in how they're employing the capabilities that they have, including their drones and their longer-range fires and so forth. That's what is leading to this accumulation of progress.

Russia is also adapting and learning from its mistakes. They are now producing more weapons and more rockets, more missiles, more drones than before. Who is technologically better off right now — Russia or Ukraine?

Each side has been doing a lot of impressive innovation. We see that from the Ukrainian side with what is presumably Ukrainian weapons systems that are bringing the war to those in Moscow, in other oblasts [regions] within the Russian Federation.

But, clearly, Russia has an economy that is many times the size of Ukraine, despite financial, economic and personal sanctions and export controls. And it obviously has a population that is three to four times the size of Ukraine as well. This really underscores the vital necessity that all of the NATO nations, the US, Germany, all of the others continue to provide all the support that we possibly can, both in the short term to ensure that Ukraine has what it needs to continue this offensive, which could go for several more months until the rain starts to slow it down and vehicles can't go cross country.

But then also to be thinking ahead — to enable them for the fighting season that will start next year — so that they can continue to liberate their territory, noting that Russia has been learning, they have been adapting.

You see that in the defense that [Russians] have established in southern Ukraine. You see it with better use of electronic warfare, you see it with the use of drones as forward observers for artillery and for rockets and a host of other ways, which is difficult, obviously, especially given that the Russians, probably the first year or so, did not particularly distinguish themselves on the battlefield, to put it mildly.

You mentioned next year. What  changes do you expect to see in this war by next year, by the spring of next year?

Well, the first change will be what Ukraine achieves during the course of this offensive. And does it put them in a position, for example, to interdict the line of communication that connects Russia through southeastern Ukraine with the forces that are north of Crimea? Can they disrupt, degrade the routes that come from Crimea on roads and bridges into southern Ukraine? Can they further isolate Crimea? Can they take down more of the naval and air bases? There's an awful lot that is going to continue during the course of this calendar year.

But what I'm getting at is that we need to prepare to help Ukraine for the long haul, and that's what NATO's focus should be.

Interview conducted by DW's Anna Pshemyska in Kyiv.

This interview has been condensed and edited for clarity.

Edited by: Darko Janjevic