The Russians have pushed against weakness using the tools they have available. That's it. It's a subliminal war that relies on the West going along with Russia's denial that they are doing anything at all let alone anything wrong.
There is no limit to this approach if we go along.
Anything other than recognizing that Russia is simply pushing against weakness is just PowerPoint fodder and pointless articles about the subtle genius of Putin and his security apparatus that amounts to analysis paralysis.
Seriously, would the West have done better in the 1930s by defining some "hybrid war" doctrine Germany's actions to inflate their currency to make reparations payments nothing and impoverishing Germans to gain sympathy for Germany in the West; re-militarizing the Rhineland without war; an information war/bloodless takeover of Austria; ethnic appeals to take the German-populated Sudetenland from Czechoslovakia; and a bullshit diplomatic offensive for a "reset" agreement between the West and Germany that didn't stop the subsequent German takeover of the rest of Czechoslovakia?
That got us a bloody World War II.
Or would the West have been better off just getting off their comfortable war-weary asses and actually stopping Germany while Germany was still weak from defeat in World War I?
Not that I'm saying Putin is a Hitler who is dead set on war with the West. Although this age does have an eerie inter-war vibe about it, I say.
And nukes change the calculations a lot, of course.
But there are people willing to fight Russia right now. Help them stop the Russians and stop trying to define what Russia is doing in some grand strategic concept as the alternative to friggin' action.
UPDATE: I don't give nonsense like 4th generation warfare much attention:
“War has changed” has become a common refrain in modern pop culture. Defence analysts and armchair generals alike tell us that the character of modern war is unlike that of any previous era. Where once the primary form of warfare was counterforce, with armies fighting armies, the primary form of modern war is that of armies fighting insurgencies, or so the theory goes.
I'd rather study the Boer War or the pacification of Wales than listen to any theorists drone on about 4th generation, or hybrid war, or whatever (remember that netwar nonsense?).
Russian "hybrid" war consists of Russia denying they are committing aggression and the West going along with that fiction.
Ultimately, it is a war of one nation taking the land of another. A "subliminal" war, as I called it early on, but a war.
Fourth generation warfare is any insurgent or terrorist with an internet connection, built up by outsiders divining deep and sophisticated reasoning behind their ordinary actions. Once an internet connection meant email and now it means social networks.
Is all that junk spun up in the past still believed when the so-called practitioners of this "flat" warfare actually considered it necessary and desirable to create a state--the proto-caliphate of the Islamic State in Iraq, Syria, and other regions?