The Russian war against Ukraine seems to be intensifying. Who can put an end to fighting — and how?

Russian President Vladimir Putin has declared his goal of "neutralization and disarmament of Ukraine," but Ukrainian forces continue to wage a surprisingly successful resistance to the invasion.

On Friday, in a one-hour phone call, German Chancellor Olaf Scholz urged Vladimir Putin to halt military action and start negotiating. This follows similar initiatives by French President Emmanuel Macron and other Western leaders.

Ukrainian President Volodymyr Zelenskyy indicated a readiness for direct talks with Vladimir Putin. But such a scenario seems unlikely. In the past, Putin has aimed vitriol at the Ukrainian leadership and indicated an interest in negotiating directly only with US President Joe Biden.

"I am deeply convinced that sooner or later we will come to an agreement between Ukraine and Russia, probably also between Russia and the West," Marcel Röthig, head of the German Friedrich Ebert Foundation's office in Kyiv, told DW. "Every war comes to an end, and usually it comes to an end with an agreement following negotiations," he said, speaking from Germany.

Who could bring Putin to the negotiating table? Röthig said that such talks could be mediated by very different actors, ranging from Israel, Turkey, or Finland to the United Nations or a special advisor from the EU.

China may emerge as a mediator, he believes, as Beijing could wield some influence over Putin. "China doesn't have an interest in a destabilized Europe and destabilized markets. And they are the last remaining big economic partner for Russia, so Putin desperately needs Chinese support."

But so far, Putin does not seem to be interested in top-level talks at all. "I fear that he has not yet seen enough casualties to allow for his war aims to change," said Gustav Gressel, a senior policy fellow at the Berlin office of the European Council on Foreign Relations (ECFR).

Could Russia's military be defeated?

But if the Russian troops continue to find it hard to get the upper hand, Gressel told DW, pressure on Putin may mount. If the Ukrainian troops can hold out "for another week or so we'll see whether Putin will agree to one of the many ideas for a compromise that there are," he said.

But is it entirely unthinkable that the Russians will have to retreat? "Never underestimate the Ukrainians," Gressel said. "They have learned a lot since 2014. It is a combat-proven army and they are very much determined to fight for the survival of their country."

If the Ukrainian forces continue to inflict heavy losses on the invaders, Putin might be forced to withdraw. "We should remember Stalin", said Gressel. "He was not somebody who had high regard for human lives, and he gave up on Finland after 40 days. It was considered too much damage for the Soviet Union as a great power being embarrassed by not being able to conquer Finland quickly."

Sanctions and a possible economic collapse of Russia could become another factor forcing Putin to reconsider his goals. If he lost the support of part of the nation's elite or if an anti-war movement gained momentum in spite of repressive measures, he might also be inclined to withdraw his troops.

Reports of a Russian attack on the Zaporizhzhia nuclear reactor on Friday sent shockwaves across Europe. German opposition leader Friedrich Merz, from the center-right Christian Democrats, told German public broadcaster NDR that a targeted Russian attack on nuclear power plants would endanger all of Europe and could constitute a reason for NATO to get involved as a matter of self-defense. But Chancellor Olaf Scholz ruled out any involvement, saying it was "completely clear that NATO and its member states will not take part in the war."

Ukrainian President Zelenskyy appealed again to the West to enforce a no-fly zone over his country. Yet NATO members have repeatedly ruled this out, saying that the mutual defense bloc would only get involved if Russia were to attack one of its members.

"Everyone knows where that would lead us. It would lead to the fact that NATO military would get into direct combat activities with the Russian army. That would lead us into an escalation that none of us would ever want because it's basically the path to the Third World War." In such a confrontation, even a nuclear doomsday scenario might unfold.

Territorial bargaining chips

So if Russia has problems bringing all of Ukraine under its control and Ukrainian forces are also unable to drive the Russians out — what could be a compromise?

One could be the agreement to create a federal Ukraine, with special status for the Donetsk and Luhansk regions that have partly been under the control of Russia-backed separatists since 2014.

"It might also be that Ukraine is ready to give away part of its territory, like the Donetsk and Luhansk regions or Crimea," said Röthig. But this would compromise Ukraine's territorial integrity and would be hard for Kyiv to accept.

Ukraine's neutrality might be another option to put on the table. But again, Ukraine would have to concede basic principles. "I would assume that Ukraine would have to withdraw its NATO ambitions, remove the aim of joining NATO in the future from its constitution," Röthig said.

And if Ukraine were to make concessions far-reaching enough for Putin to accept — would the Ukrainian people accept them too? "The good thing is that Ukrainian President Zelenskyy has a kind of nimbus at the moment, he has a very high rate of public support," said Röthig. "That is why he is now able to sell a compromise to the Ukrainian people."

But Röthig points to European history and urges caution. After World War I (1914-1918), defeated Germany felt deeply wronged and humiliated by the provisions for peace set out in the Treaty of Versailles.

If the country's leaders were to concede too much, Röthig says, Ukrainian fighters could feel stabbed in the back and refuse to adhere to the outcome of any agreement.

"Ukrainians at the moment have the feeling they could win this war, which is a false feeling because, in the long run, they will not win this war," said Röthig. "Patriotic fighters might argue that Zelenskyy sold the country and that he gave in to the Russians who would otherwise have been defeated."

Any peace that is seen to have been dictated by Russia could lead to continual uprisings and guerilla warfare.

Pressure from within Russia

"We always thought Putin is very rational deep inside," said Röthig. But this idea, in his view, has been proven wrong: "At the very end of the day, however, he is acting purely emotionally and that makes him unpredictable. What I hope for is his environment, his direct advisers. But we don't know how many of them he's really listening to and what they actually tell him."

The German chancellor, for one, has described the invasion of Ukraine as "Putin's war." So what if Putin were ousted?

Sergey Medvedev from the Berlin-based "Dekabristen," an NGO supporting grassroots initiatives in ex-Soviet countries, does not rule out this scenario. "As the first dead people arrive in Russia now and in the next days, even Putin supporters may begin to think: 'Do we really need this war? And do we really need this regime?'"

But Röthig is very cautious about such a scenario being discussed in the West as a way out of the Ukraine war. "I think regime change has never been a good idea because we do not know what it leads to and what kind of instabilities that would mean for us. I think this is nothing we should even think about."