The “boundless” friendship that Xi Jinping and Vladimir Putin staged in Moscow in March actually included a blinking red line. China’s president has reportedly seriously warned his Russian counterpart against resorting to nuclear weapons, even tactical ones. This was confirmed by the Financial Times on Wednesday, which was based on Chinese “advisors” and “former senior officials”.

The Kremlin denies that Xi Jinping, in one of the strange trips abroad since the pandemic, marked the ground in this way. “It is a fiction”, said the spokesman, Dmitry Peskov.

However, several experts warn that, if the Russian army were to be cornered by an increasingly large and sophisticated flow of weapons from 29 NATO countries – all but Hungary – the temptation to using tactical nuclear weapons could become irresistible.

These could be used to slow down the hypothetical Ukrainian advance. The most eminent political scientist of the American Realist School, John Mearsheimer, has no doubt that Moscow would resort to these weapons in the event that the rule of Crimea was threatened. In addition, Russian military doctrine foresees the use of nuclear weapons in the event that the survival of the State is in question.

In any case, following the interview with Xi Jinping – and recently – Putin has declared in several forums that he does not plan to use nuclear weapons “because there is no need for it. We are incinerating the Leopard tanks and when the F-16 fighters arrive we will also destroy them”. The aforementioned Mearsheimer considers that the enormous difficulty of the Ukrainian offensive to overcome the Russian entrenchment has at least one positive aspect: it moves the world away from the nuclear abyss.

However, for months now, in countries bordering Ukraine, the demand for iodine tablets, supposedly capable of inhibiting the worst effects of nuclear radiation on the thyroid gland, has skyrocketed. In Eastern Europe, the way in which the Chernobyl accident multiplied thyroid cancer cases for many years, especially in the case of children, is still fresh.

The main concern now is with another Ukrainian nuclear power plant, which is also the largest in Europe. Control of the Zaporizhia reactors was wrested from Ukrainian soldiers by the Russians in March last year, and since then the two armies have played with fire and used heavy artillery in the vicinity.

In recent days, the Ukrainian president, Volodymyr Zelensky, has accused Russia of “mining” the roof of the plant with the supposed aim of “causing an accident” and sabotaging its – limited – progress on the front.

The allegations have not been corroborated by observers on the ground from the International Atomic Energy Agency (IAEA). They have also been rejected by Moscow, which warns against “a false flag attack”. Kyiv has failed to convincingly explain what interest Russia might have in contaminating its own troops with radioactivity in the Russophone and partly Russophile areas it already controls or aspires to control if the war drags on.

The head of Ukrainian military intelligence, Kirilo Budanov, after fueling suspicions of sabotage, claimed yesterday that the risk in Zaporizhia “has begun to decrease”.

Without leaving the scenario of madness, it must be remembered that, in case of wanting to resort to nuclear blackmail, Russia has at its disposal hypersonic precision missiles capable of destroying nuclear power plants in nationalist areas controlled by Kyiv.

China, which last year increased trade with Russia to a record level, does not want, in any case, to worsen relations with Europe. Looking the other way in an invasion scenario is not the same as doing it in a nuclear holocaust scenario. It is also true that, of the five formal nuclear powers, only China refuses in its doctrine to be the first to push the button.

Meanwhile, a threshold has already been crossed – according to Moscow’s opinion – with the supply to Ukraine, by the British side, of ammunition with depleted uranium. It is more capable of piercing tank armor, but, as seen after the invasion of Iraq, it also leaves decades-long traces in the air, soil and water, and multiplies fetuses with malformations.

The British leaks come as US Treasury Secretary Janet Yellen begins a four-day visit to Beijing, two weeks after Foreign Secretary Antony Blinken’s trip. Another attempt to restore relations between the two great powers, very rare due to Taiwan.

Today President Zelenski will meet in Istanbul with his Turkish counterpart, Recep Tayyip Erdogan. Although the explicit aim is to save the grain transit agreement – ??which expires in ten days – the war and the expansion of NATO will also be on the table, on the eve of the Vilnius summit. Yesterday, a Swedish judge applied the new anti-terrorist legislation to jail a Kurdish exile who collected the revolutionary tax from the peasants.