Russia wants to turn Ukrainian Kharkiv into uninhabitable "grey zone"

British media outlet The Economist, with reference to military sources in Kyiv, assumes that Russia decided to turn the city of Kharkiv into a "grey zone" uninhabitable for civilians.
The Economist, in the story titled The Kremlin wants to make Ukraine’s second city unliveable.
"The escalation had military sources in Kyiv suggesting that Russia has resolved to make the city a "grey zone", uninhabitable for civilians."
Meanwhile Ihor Terekhov, mayor of Kharkiv, strongly refuted this hypothesis. In an interview conducted at a secret location in the industrial quarter, Terekhov says residents of his city have no intention of giving up.
Things were worse at the start of the war, he argues, when all but 300,000 of the city's pre-war population of 2 million people fled.
"How can you make a city like this a grey zone? People won’t leave, because they have already left, then returned. They have been tortured enough already."
Terekhov stated that it was quite challenging to power the city up without power stations or working transformers, but they have managed to do it.
"If I told you how we did it, that too would be targeted," he added.
The Economist notes that many of Kharkiv’s problems would be solved if the West provided more air defence systems or F-16 fighter jets that could push back the Russian fighter jets carrying the gliding bombs. It adds that Russia destroyed some of the Western-supplied Patriot air-defence units that Ukraine had been using to protect cities like Kharkiv.
Russia’s exact intentions are not clear at this stage, though there are certain signs that it is preparing for a major summer offensive.
"A Ukrainian source with knowledge of the intelligence picture said Russia is currently training six divisions, approximately 120,000 troops in eastern Siberia," the article says.
The Economist believes that "Kharkiv is one of several possible directions for a future assault". It is not the most likely, but it has already been heavily trailed in Russian media.
"That might indicate a Kremlin information campaign to frighten Kharkiv residents. Or it could be a nod in the direction of a pro-war camp agitating for a fiercer response to Ukraine’s frequent attacks on Belgorod, which are also causing unease in Western circles," – the material says.
The Economist admits that the military operation of invading Kharkiv would be an exceptionally complicated mission for Russia.
"Taking the city would require breaking through Ukrainian defences and encircling it, which Russia is nowhere near being able to do; establishing air superiority, which is not a given; and winning a bloody urban campaign," – The Economist explains.