Rain-soaked farmland, tire tracks filled with water. Since Ukraine retook the city of Kherson in early November, boggy mud has been a constant feature in the flood of images coming from the front lines of the war — in the south of the country as well as the east.

At the same time, according to Kyiv Mayor Vitali Klitschko, Russia is bombing people into the "worst winter since the Second World War." Power cuts are frequent almost everywhere in Ukraine, with electricity available only by the hour.

Authorities in Kyiv are trying to help people by supplying heated tents and standalone generators. Russia "has already caused some very serious destruction of infrastructure that cannot be repaired quickly," Ukraine and Russia expert Nico Lange of the Munich Security Conference told DW.

Spare parts for destroyed substations and other energy infrastructure are being delivered to Ukraine, but even replacing "certain transformers or certain components" takes a lot of time, Lange said.

Heavy losses for Russia

Russia's army urgently needs time to rest and regroup in Ukraine, said Margarete Klein, an analyst with the Berlin-based think tank the German Institute for International and Security Affairs (SWP). "They are recording heavy losses in material and personnel," Klein said.

Russian soldiers who were mobilized earlier in autumn seem to have been of little help. "In order to make the armed forces more effective in combat, it is not enough to send poorly trained and equipped reservists quickly to the front." They served mainly as cannon fodder. "To be able to better train a potential new wave of reservists," the Kremlin needs time. "Because many of the potential instructors are themselves engaged in combat."

Denying Russia's army this time appears to be the Ukrainian armed forces' most important strategic goal this winter. As a humanitarian catastrophe looms for the civilian population, the sub-zero temperatures typical of the region could soon provide Ukraine with military advantages.

Waiting for the ground to freeze

In the east of the country, where Russia's army occupies large parts of the Luhansk region, Ukrainian forces are "relying on the ground to freeze," Lange said. For example, the army currently has "a lot of vehicles on wheels" in the northeast of the country. For Ukraine's army to "play to its strength: mobility," the ground needs to be frozen solid.

Along the front lines in the east, the Russian army is displaying its superiority with mobile rocket launchers from the Soviet-era Grad system. Russian forces are covering the Ukrainian positions with constant shelling and so far have found it easy to replenish their stocks.

This means that it is crucial for Ukraine to cut off those supply routes — using Western artillery on wheels, such as the French Caesar system. That is why it is essential for the ground to be frozen solid, instead of muddy and difficult to traverse.

"As soon as the ground freezes, I think that more action will again be possible from the Ukrainian side," Lange said. "We seem to be waiting for this," he said in relation to "the axis of attack in the Luhansk region."

In just a few weeks, another problem faced by Ukraine's army is expected to be solved: The Western artillery systems that troops are using intensively have been worn out, but by "mid-December" a repair center for weapons such as self-propelled howitzers should be ready across the border in Slovakia. "German industry is now busy setting up the servicing center on our behalf," German Defense Minister Christine Lambrecht told the Frankfurter Allgemeine Zeitung news outlet. "A large delivery of spare parts — about 14,000 items — will be made available."

Lack of ammunition

"For Ukraine, it is all about keeping the momentum," Klein said. "The Ukrainian army has shown that it can very cleverly exploit the weaknesses of the Russian side."

Ukraine's arm, however, also faces a own lack of ammunition, Lange said. "For example, Ukraine is using missiles for air defense systems faster than they are being produced." This also applies to simple artillery ammunition, which Russia in turn has an unlimited supply of.

Thus, this war is now developing into a race for ammunition. Putin is speculating, according to Lange, that the Ukrainian air defense is running out of it.

But the 50 supporting countries in the Ukraine Defense Contact Group, spearheaded by the United States, are delivering further air-defense systems. "Ukraine's air defense is improving," Lange said. Russia is reacting to this by firing even more medium-range missiles and drones at civilian infrastructure.

This is becoming increasingly difficult for the Kremlin. There are pictures that show missiles that belong in the strategic reserves are already being used. "And it is not so simple for Russia to make more of these types of missiles, because it is under technological sanctions, and it does not have the [micro]chips and technology for them," Lange explained.

The winter phase of Russia's war against Ukraine is like a tug-of-war. How it will end depends on whether Kyiv can alleviate the humanitarian crisis with western help, whether Ukrainian air raid defenses can be further strengthened, and whether the Ukrainian army can disrupt the Kremlin troops on the frosty ground of the front lines so that they have no chance to rest or regroup.

Few experts envision a chance for peace soon and an end to the human suffering in Ukraine. "I see no willingness from the Russian side to negotiate seriously at present," Klein said.

This article was originally written in German.

While you're here: Every Tuesday, DW editors round up what is happening in German politics and society. You can sign up here for the weekly email newsletter Berlin Briefing.