Two days ago, the Ukrainians (read: the Americans) performed a successful drone attack that damaged the Voronezh radar station in Russian Krasnodar.
This radar is part of the nuclear early warning systems. An attack to nuclear early warning systems is something that would traditionally precede a sneak first strike, and as such is taken extremely seriously. This is absolutely not something Ukrainians would have done on their own, because it makes no sense in context of the Ukraine war theatre. This is something unprecedented and extremely serious, basically comparable to a special force diversionary attack on nuclear silos with the goal of disabling the ICBMs.
This never happened before, and in traditional nuclear doctrine this would have a very serious answer – raise the readiness level of the nuclear forces to the equivalent of DEFCON 2, and launch if any redundant radar or satellite detection systems are compromised. Also, the answer to this would traditionally be destruction of the American radar stations in Poland, Romania and so on, that are a part of the nuclear war toolkit.
I cannot overstate the seriousness of this. We are in the initial phase of a nuclear war between NATO and the Russian Federation.
So far, the fact that the Russians kept this under wraps means that the thing is too serious for politics and news, and they didn’t want to paint themselves into a corner in ways that would mandate an instant nuclear strike.
Update 27-5-2024: Yesterday another Voronezh radar station, this time in Orenburg, was hit. There is no indication of the level of the actual damage to the station in question, which probably means that there was little to none, but the intent itself creates a pattern.
Update 29-5-2024: Third attack, Voronezh station in Krasnodar again.