Scott Elaborates On The Matter ...

 ... as a military professional.

Karaganov is NOT military professional, he is a demagogue who failed to insert himself into any position in the Russian Foreign Ministry and was always in the business of self-promotion and self-proclamation of being "adviser" to whoever was a flavor of the decade. He is not and never was any "adviser" to President Putin and he has no a faintest idea about issues related to Russia's Military Doctrine and the use of nuclear weapons (Foundation of State Policy on Nuclear Containment). In general, he is an incompetent hack who simply uses his position of being born and tied to privileged Soviet families and that's the extent of his "skills". In fact, his statements are the statements of a media attention-seeking whore. He is fake. 

Now, per strikes--all indicators are that Russia will strike Europe. Russia doesn't need to use nukes because she has more than enough conventional means for both destruction of a critical industrial infrastructure involved in support of 404 and, if it comes down to it, decapitating governments of hostile countries. The conditions for the use of nuclear weapons are not met yet. But they are already within the legal vicinity for the possible use. Here they are:

19. The conditions determining the possibility of the Russian Federation using nuclear weapons are:

a) receipt of credible information regarding the launch of ballistic missiles attacking the territory of the Russian Federation and/or its allies;

b) the use by an adversary of nuclear weapons or other types of weapons of mass destruction against the territory of the Russian Federation and/or its allies, or against military formations and/or facilities of the Russian Federation located outside its territory;

c) an adversary’s impact on critical state or military facilities of the Russian Federation, the disablement of which would lead to the disruption of the retaliatory actions of its nuclear forces;

d) aggression against the Russian Federation and/or the Republic of Belarus—as participants in the Union State—involving the use of conventional weapons, which poses a critical threat to their sovereignty and/or territorial integrity;

e) receipt of credible information regarding the mass launch (takeoff) of aerospace attack assets (strategic and tactical aircraft, cruise missiles, unmanned aerial vehicles, hypersonic and other aircraft) and their crossing of the state border of the Russian Federation.

Other considerations come into play here, but pp. d is "getting there". Karaganov doesn't understand operational let alone technological implications of all that--he simply has no tool kit or background to pass judgement on the matter. But that brings us back to the starting point--Russia has enough conventional means to strike at any facility in Europe and the US IS NOT coming for a simple reason--it has no resources. Demilitarizing NATO was one of the key strategic aims of SMO (once it became clear that the US sabotaged Istanbul talks) and Iran has demonstrated it fully. Who will be hit first? Yeah, I am inclined to see Germany "getting the message"--it is long overdue.