While Russia for the past several months has rained missiles on Ukrainian cities with impunity, Ukraine is now hinting that Moscow might soon get a taste of its own bitter medicine. A top adviser to President Zelensky, Mikhail Podolyak, said that “the internal escalation of the war in Russia is inevitable,” adding that “such cities that are pampered, lazy, who thought they live in a different reality, like Moscow, St. Petersburg, Yekaterinburg, will be subject to blows.”

Mr. Podolyak, who oversees Mr. Zelensky’s strategic communications, offered no specifics but told a Ukrainian podcaster that his prediction is fueled by the “logic of war.” He stopped short of saying that Ukraine would actually attack Russian cities in Russia. Yet Ukrainian drone strikes have previously targeted airbases in the Saratov and Kaluga regions inside Russia, so there is some precedent. Also, Ukraine announced this month that it was developing a strike drone with a range of more than 600 miles. Moscow is about 540 miles north of Kyiv.

In a sign that the Ukrainian adviser’s warning is not to be taken lightly, Russian air defense systems have already started appearing at various locations around the Russian capital as well as near a residence belonging to Vladimir Putin outside Moscow. In a meeting earlier this week with the regional governor of Belgorod, which borders Ukraine, Mr. Putin said that “practical combat work has shown that Russia’s air defense is one of the best in the world.” He boasted that “the United States produces Patriot missiles but we produce three times as many such missiles in our country — even more than three times as many.”

Ukraine’s air defenses certainly have been kept busy. The embattled country’s military said Russia launched 55 missiles at targets around Ukraine on Thursday alone, with 47 successfully shot down. Nevertheless,  Ukrainian authorities said that a combination of Russian missile and kamikaze drone attacks throughout the country caused at least 11 deaths. 

The war remains as hot as the winter is cold. Amid concerns that enough of the high-tech battle tanks that have now been authorized by Germany and America may not reach Ukraine’s frontlines before the spring,  when Russia is widely thought to be planning a fresh offensive, debate about the scope of the war is also heating up at Washington. It is about more than a growing number of calls by Republican legislators for audits of the billions of dollars in aid flowing to Ukraine. 

During a Senate Foreign Relations Committee hearing on Thursday titled “Countering Russian Aggression: Ukraine and Beyond,” there was a testy exchange  between Senator Paul, Republican of Kentucky, and the undersecretary of state for political affairs, Victoria Nuland.

Mr. Paul asked Ms. Nuland if Vladimir Putin could be a target for prospective Ukraine war crimes prosecutions at the International Criminal Court at the Hague. Ms. Nuland replied that the Russian leader “is certainly guilty of prosecuting war crimes, he is certainly the leader of this illegal aggression.” In response, Mr. Paul said, “So it sounds like the [Biden] administration would favor taking him to the Hague?” 

Ms. Nuland, a Foggy Bottom stalwart, proffered: “We are looking with our partners at the appropriate judicial mechanism” — but that is not what the rarely reticent Mr. Paul wanted to hear. 

“If you’re really thinking that ultimately there might be a peaceful settlement that doesn’t involve unconditional surrender by the Russians or vice versa by the Ukrainians, you might put some thought into the fact that by saying he’s guilty of war crimes and that it’s a possibility that he’s going to the Hague, that it makes any kind of peaceful settlement less likely to prosecute a peace or engage in peace,” he said.

Mr. Paul then admonished Ms. Nuland: “I think you’re basically saying this war is going to go on forever.” He added that “if you want to picture devastation and you see Ukraine now, in five years it will be worse…. If you preclude peace I think you will inevitably make it worse.”

Whether the senator’s concerns are legitimate, overstated, or a mixture of both can be debated, but curiously the Russian press — which seizes on any statements by American officials about Ukraine with a falcon’s grasp — latched onto something uttered by Ms. Nuland. It was in response to a question from Mr. Paul about the possibility of easing of sanctions on members of the Russian state Duma in exchange for Russia doing the same with respect to American legislators it has sanctioned, as a means of theoretically fostering dialogue.

While Ms. Nuland did not answer the question directly, she did have this to say: “In the context of a Russian decision to negotiate seriously and withdraw its forces from Ukraine and return territory, I would certainly favor and I believe Secretary Blinken would also favor sanctions relief.”

That relief, though, will not be forthcoming soon as Moscow digs in and the war grinds on. Furthermore, on Thursday the treasury department sanctioned 17 more Russians on top of the 893 Russian officials already sanctioned. The additions included the deputy Russian prime minister and head of the ministry of trade and industry, Denis Manturov, as well as the head of the Russian federal penitentiary service, Arkady Gostev.

Companies linked to the Wagner private military group were also sanctioned, and Washington formally designated the group itself as a transnational criminal organization. Any U.S. assets held by the group, which is led by Putin crony ​​Yevgeny Prigozhin, will henceforth be frozen. 

In a more symbolic move, the state department will also impose visa restrictions on 531 members of the Russian armed forces on account of their roles in the war in Ukraine.