Consider the facts that Article 5 is the cornerstone of NATO alliance, how the collective military strength of NATO massively dwarfs that of Russia, how Russia has fared in Ukraine, how depleted it is. I absolutely cannot fathom how Russia could even entertain the idea, let alone execute it, because the outcome of a conventional confrontation is very predictable, whereas going nuclear means everybody dies and nobody wins.
There's an assumption embedded in this that NATO's possession of overwhelming conventional force means that Russia will be cowed into inaction.
This is potentially wrong for several reasons.
Firstly, people do sometimes fight to the death. It's empirically not that unusual. It's especially not that unusual in circumstances that resemble this context where one side acts arrogantly thinking it can simply cow the other with overwhelming violent force, such as badly-governed prisons, or even Israel-Palestine.
The evidence shows people only consistently respond to threats in quite low-stakes competitions, and that high-stakes conflicts are either regulated by shared ideology or else they escalate indefinitely to maximum force.
Secondly, if Russia thinks the West are in an arrogant mode of thought based on their military supremacy, it will launch a war of mutual destruction, because you can't reason with or coexist with such an arrogant enemy, and Russia's destruction would already be assured when facing such an enemy (given at how close proximity the West already is - there's no buffer zone that Putin can even consider ceding, like there was in the Cold War with the USSR).
So it becomes a one-way bet - at worst you deal fatal destruction to a mortal enemy you can't beat, and at best you actually alter the situation so radically that your enemy is weakened and equalised with you (or the successor regimes on each side are equalised).
Thirdly, there is a real prospect that the NATO alliance would fold when faced with the need to escalate to worldwide nuclear winter.
This is because Putin leads a single regime fighting on its own territorial doorstep, whereas NATO consists of many individual regimes, many of which have no great individual interest at stake (nothing to die for, I mean).
America, France, and Germany would find it impossible to mobilise their general populations to fight on some foreign Eastern European border hundreds or thousands of miles from their territory, and by implication they'd find it impossible to accept the fate of their own regimes over some faraway skirmish. Indeed their populations might even be jubilant about the collapse of the EU single market covering these territories, because the liberal leaderships (and their ideas) often stand in opposition to popular ideas.
It doesn't matter how much NATO stamps its feet and members merely say they are determined to die for its treaty obligations. The Russians will look behind the rhetoric and analyse the reality of how the NATO alliance is assembled, and how it consists of a large array of leaders with conflicting interests and rooted almost entirely in local territories.
Does NATO have a single command and control leadership who consider the entirety of NATO to be their national territory? And do they have a population who think the same, and can be mobilised in defence of every corner of that territory? The answer is no - not by a long shot.
The real danger for the world is not that Putin actually overplays his hand. It would be that Western liberals believe they have a much stronger hand, and cause their own destruction as other regimes feel forced to go all in to correct perceptions.
In reality, there's no sign that anyone at the forefront of Western politics has any of these illusions - the US has been dilatory and restrained in its escalations with Russia, doing little more in Ukraine than they did in 1980s Afghanistan of flooding weapons, bankrolling local extremists, and denying any peace to the USSR.
The reality is also that the US was hoping the existing level of pressure would already have caused Russia to destabilise politically or economically. But it's actually caused considerable instability for the West, too.