HARI SREENIVASAN: For more on what’s happening on the ground in Ukraine, I’m joined by Andrew Kramer of The New York Times. He joins us from Donetsk.

So, Andrew, you were visiting a town where the Russian troops were streaming in. Describe that scene to us.

ANDREW KRAMER, The New York Times: Yes, this was in the town of Novoazovsk on the Azov Sea. And we were standing on the outside of the town speaking with Ukrainian soldiers who were retreating.

These soldiers were convinced they were fighting the Russians. At least many of them were. We didn’t see the troops coming in, but they were said to have come across the border from Russia into Ukraine. It was a very chaotic scene. And, in fact, a day later, that town was seized by the pro-Russian forces.

HARI SREENIVASAN: You also spoke of locals in that area. What did they think about what’s happening?

ANDREW KRAMER: Well, people here who support the Russian cause are obviously cheered by this development. The rebel organization had been on its last legs militarily in recent weeks.

The Ukrainian army was closing in on towns of Donetsk and Luhansk. And now there’s been a reversal of fortunes, a turning of the tide here. The separatists and, according to Ukrainian government, with the support of Russia, has moved across the Russian border and has now opened a new front in the south along the seashore with the cities of Novoazovsk and Mariupol as the objectives.

Now, a rebel commander I spoke with said the intention is to form a defensive triangle out of these two cities and Donetsk and hopefully force the Ukrainian government into settlement talks on more favorable terms.

HARI SREENIVASAN: What’s the impact on the cities that you’re — you’re in Donetsk now. But what’s the impact there on what’s happening in these other towns?

ANDREW KRAMER: For now, in Donetsk, little has changed. We had an artillery barrage come into town today that killed two people, hitting residential areas. The Ukrainian government is keeping up its pressure on Donetsk.

The assumption is that forces will be diverted from here to the south to address this new risk, this new push by the pro-Russians and possibly with support of Russian supporters coming in across the border. That’s the hope at least of the separatists living in this town. It’s a setback for the Ukrainians who are hoping to end this war quickly and on their terms.

HARI SREENIVASAN: Can you feel a level of tension increasing or decreasing from the events in the past week?

ANDREW KRAMER: The tension is certainly increasing, particularly in the towns and villages affected.

We drove along a 75-mile stretch of highway from here in Donetsk to the area where the battle is taking place and it was almost wholly deserted. You would see only a few cars carrying refugees, burned-out military vehicles, and people who were very concerned, obviously, about this new development and the violence which is coming to their communities.

HARI SREENIVASAN: Is there a cognition of what’s happening and how the rest of the world is paying attention? Do the people in Ukraine, the ones that you speak with, care about what’s happening at NATO or whether this is called an invasion or an incursion?

ANDREW KRAMER: People in the areas that have been shelled are mostly concerned about everyday concerns, like fetching water and food and staying out of the way of danger.

There is certainly, among the rebels, a larger understanding of the context of this war and this conflict. Ukraine has now said — the president of Ukraine has said today that Russia invaded. NATO was more cautious, saying that Russia had carried out an incursion into Ukraine. In any case, what’s clearly happening here is a cross-border military action in Europe, and the consequences are very unpredictable.

HARI SREENIVASAN: Andrew Kramer of The New York Times joining us from Donetsk, thanks so much.

ANDREW KRAMER: Thank you.

GWEN IFILL: Jeffrey Brown picks up the story from there.

JEFFREY BROWN: And to go deeper into these developments, I’m joint by Andrew Weiss, a former director of Russian, Ukrainian and Eurasian affairs at the White House National Security Council. He’s now with the Carnegie Endowment for International Peace. Andrei Tsygankov, a political science and international relations professor at San Francisco State University.

Andrew Weiss first, how do you describe what’s going on and who are these Russian soldiers? What role are they playing?

ANDREW WEISS, Carnegie Endowment for International Peace: I think, throughout the crisis, we have seen the Russians try to disguise their ultimate moments.

So we may have a new front on the southern — southeastern — southeastern border between Russia and Ukraine. We also might have a Russian attempt to create a land bridge between the Russian border and Crimea, which would allow them to supply Crimea more effectively in the future.

JEFFREY BROWN: Would you use the word invasion, incursion? What word would you use at this point?

ANDREW WEISS: Well, there’s this interesting semantic game being played in Washington today, where U.S. officials are trying very hard not to use the word invasion, so you have the State Department spokesman, Jen Psaki, saying it’s an incursion.

What I think the reason for that is, is that U.S. officials, as President Obama said today, is they’re trying to avoid any perception that there’s a U.S. military response in the offing. So they seem to be somewhat downplaying what’s happened.

But, at the same time, I think privately people are very worried that what we’re seeing is a dramatic escalation.

JEFFREY BROWN: Andrei Tsygankov, what do you call it? How much of an escalation do you see?

ANDREI TSYGANKOV, San Francisco State University: I would call it an escalation, and, as Andrew Weiss just described, the second front opening.

And certainly this is — this is something that’s been going on for quite some time. We have seen the Russians’ assistance before. And this is also not major news. What’s actually new is that the Ukrainian side is beginning to lose on the military front and that in, Minsk, Petro Poroshenko, Ukrainian president, has not gotten what he expected to get, and that Germany is beginning to pressure Kiev for peaceful solutions.

So, now what is happening, in addition to Russia’s escalation, is that Ukraine, Kiev is launching a P.R. offense against Russia.

JEFFREY BROWN: So, you’re seeing this as coming from weakness by the Ukrainians, as opposed to more aggression by the Russians?

ANDREI TSYGANKOV: I see both. I see both, but Russia’s intervention is not something that has happened just now. Russia has been assisting the rebels, eastern rebels before.

As we know, Russian volunteers fought there. We know that previous commanders of Donetsk and Luhansk, and primarily Donetsk, were Russian citizens. So Russia certainly was involved. And it makes sense for Russia, if it sees itself as a great power that needs to protect its interests in Ukraine, to be involved, so it has been — it has been taking place for quite some time. This is just a new stage.

JEFFREY BROWN: And…

ANDREI TSYGANKOV: But what we also see is again that Ukraine is trying to launch a P.R. offensive against Russia.

JEFFREY BROWN: Well, Andrew Weiss, Ukraine seemed to have been doing — had — stronger militarily in many ways, which would counteract what he was just saying.

ANDREW WEISS: I think people’s expectation in recent weeks was that the Ukrainians were a roll and that it looked like the separatists were basically cornered in two strongholds, Donetsk and Luhansk.

And the question, what would Putin do? Was Putin cornered? And there’s this great vignette in Putin’s autobiography where he talks about chasing rats in the dilapidated building where he grew up in, and one day he cornered a rat and discovered that the rat was going to attack him.

I think what we have seen here is an example of how Putin wasn’t really cornered. Putin has basically at various turns in the crisis, when it looked like Russia’s status on the ropes, has chosen to escalate and he’s done that once again.

JEFFREY BROWN: So you’re seeing this quite differently from what — the description we just heard? This is Russia more on the defensive and reacting?

ANDREW WEISS: Well, it’s been restrained.

I don’t think Putin’s first choice is to mount a full-scale invasion of Ukraine. But what we have seen is that they’re not willing to lose and that when it looks like the Ukrainians are poised to do too much too quickly, the Russians raise the stakes and that that’s where we are today.

JEFFREY BROWN: Andrei Tsygankov, what’s your response? What — well, go ahead.

ANDREI TSYGANKOV: I don’t disagree. I don’t disagree. I think this is what is happening.

I think Russia is raising the stakes. But remember that Russia is raising the stakes in response to Ukrainians raising the stakes. Ukrainians have begun this anti-terrorist operations, what they called anti-terrorist operation, which is in effect is search for a military solution, and military solution to the conflict.

And Russians certainly will see this as a need to restore balance of power. For them, this is a necessity to negotiate better political conditions for their interests and values. They have major interests, such as Ukraine not to be a member of NATO, such as Ukraine not to join the European Union, but ultimately to remain relationships with Eurasian Union.

They have interests to protect Russian language speakers there, those who gravitates toward Russia. And this is something that they will be willing to defend, if necessary by military means.

JEFFREY BROWN: Just before — Andrew Weiss, just before we started, you heard word of a new pronouncement or a news announcement, was it, from Putin?

ANDREW WEISS: So, what seems to be happening ,as Andrew Kramer from The New York Times talked about, is that this Russian incursion in Southeastern Ukraine has really caused disruption in the Ukrainian ranks and soldiers are basically evacuating in a pretty sort of pell-mell kind of environment.

The Russian president, Putin, tonight has issued a statement at an unusual hour, 1:00 a.m. Moscow time, calling on the rebels not to kill the Ukrainian soldiers who are now encircled. And he is saying, open a humanitarian corridor. These people are being forced to fight. Let them go home to their families.

It’s not clear what’s going on, on the ground, whether there is this significant risk that Ukrainian soldiers are going to be sort of ground up by the new Russian forces that have been introduced. But it’s striking to me that Putin is reduced to sending out his commands via press release, and it just suggests to me that the situation is very messy and very uncontrolled.

JEFFREY BROWN: Andrei Tsygankov, you can comment on that, but I also want to know your sense of whether the Russians and Mr. Putin are feeling any impact of the American sanctions so far, whether the pressure from the West is having any impact?

ANDREI TSYGANKOV: Let me just make one observation about the situation in Ukraine.

Certainly, Russians — Russians were assisting the rebels, and the rebels were losing until recently. But, a week ago, about a week ago, they began a counteroffensive. And that’s what’s happening today. Thousands of Ukrainian troops are now encircled. That’s not sufficiently reported in Western media, but it is something that certainly helps Putin to negotiate better conditions.

This is one of the reasons why he felt so confident in Minsk. This is one of the reasons why he didn’t feel that he would need to negotiate with Poroshenko over political conditions, because Poroshenko already knows all these conditions, and the ball in many ways is in his court.

Russia can wait until the fall, until possibly winter, when it will be able also to use energy weapons. And in the meantime, the solution is only a political one. This is something that now all sides recognize. Russia recognizes this. The European Union, Angela Merkel, the German chancellor, recognizes this. Barack Obama now recognizes this.

JEFFREY BROWN: All right.

ANDREI TSYGANKOV: So it’s now essential to move in this direction.

JEFFREY BROWN: All right, Andrei Tsygankov and Andrew Weiss, thank you both very much.

ANDREW WEISS: Thank you.

ANDREI TSYGANKOV: Thank you.

This interview was originally broadcast by PBS’ NewsHour.