But europians decreased numbers of their tanks dramatically
For economic reasons only.
The could and might greatly increase the number of MBTs they have on their territory... the CFE treaty is not being observed by anyone at the moment so they can actually make as many as they want.
A bit like american ABM missiles in Europe.
however the history of American SAMS in the last 25 years have been problematic (which may also hold true with the latest Standard Missile series), less than stellar, and less of a "hit" and more of "miss" (from the Patriots SAMS' terrible performance in the first Gulf War, to the countless testing failures of the Ground-based Midcourse System aka GMD)
First of all keep in mind that the Patriot failed because it was designed to hit aircraft and not ballistic missiles. It took an average of 32 Patriots for each shot down Scud which is not to say 31 missed... most that made it to the target exploded but did not destroy the warhead of the falling missile which meant the warhead fell intact and still did damage.
Patriot was not a bad missile, though it did kill more allied aircraft than S-400 has.
I think I'm repeating myself, but tactical nukes are the second-to-last move of desperation.
Repeating something does not make it true. If Russia had promised not to use nukes first then I would agree, but they have not made any such promise.
In a situation where NATO forces are concentrated and attacking Russia why would Russia not use nuclear weapons? It is called defending yourself.
The response to a tactical nuke may well be strategic nukes - who knows. The firepower is comparable.
Rubbish. Tactical nuclear weapons are relatively small and will not be used all at once... strategic nukes are much more powerful and will all be used together.
A tactical nuke strike can be seen as a line drawn in the sand... if NATO continues the result will be strategic war... but whatever NATO is doing it might think it is worth using conventional forces, but is not worth a nuclear conflict and so could back down if Russia uses nukes. Escalating would be pointless as it leads to a place where neither side wants to go.
As an example, if you nuke that hypothetical tank formation (coming to implement this so-called "regime change") and end up obliterating a part of a NATO city... can you imagine the response?
A hypothetical NATO tank force moving into Russian territory is hardly going to end up with part of an important NATO city being destroyed... it would be likely a Ukrainian or Baltic city for which most of NATO could care less and certainly not risk escalating the conflict to the point where their cities might get nuked.
Lastly, if tactical nukes were so wonderful and could secure Russia, they would probably not spend what they are spending on conventional arms.
They don't rely on them by choice, but by their current situation.
An improved conventional force will not make tactical nukes obsolete either...
The Kiev "coup" - done by the Americans .. or not, did not involve open military operations. That difference should make this example obviously irrelevant.
Ukraine has never been and will never be a serious threat to Russia that warrants nuclear weapons. NATO forces moving into the Ukraine on the other hand is something completely different. The American coup in Kiev just shows Putin that the US is not interested in cooperation and working together and will always be an enemy. There are other directions to look for allies and friends and trading partners... eventually when Europe grows a spine and cuts the umbillical cord from the US (which seems to operate in the reverse direction to human umbillical cords BTW) they might be able to work out closer ties there too... but certainly not worth it any time soon.
I do agree that a scorched earth style nuclear response - if facing a land invasion, is possible. This also makes this whole scenario extremely unlikely.
A NATO attack by ground forces on russia is very unlikely too, but in the event do you really think they would wait for those NATO forces to reach Russian territory before they start using nukes?
Do you think NATO air power would wait till the ground forces got stuck before providing air support and trying to deal with Russian air defences?
If NATO aircraft are attacking Russian air defences do you really think the Russians would refuse to attack massed NATO forces on NATO borders with Russia?
When it comes to wars over resources - going to nukes basically guarantees that no one will win. That's not necessarily the outcome Russia would want.
Of course... Russia would much rather be invaded by NATO for its resources than defend itself and its territory. My question would be... why would NATO think a ground invasion would work any better now than it did 60-70 years ago... the Soviet Army was in a terrible state then too, but if Stalin had tactical and strategic nukes do you really think he would not use them?