there was a chap on R4 last week who felt is was a real possibility - his view was that the EU was still obsessed with its 'cooperative, win-win' end-games with regrds to Russia, while Putin not only wants to win, but he wants others (In this case, western Europe) to lose as this makes his 'win' look even bigger, both at home and for his next victim. his is a much easier game to play.
Putin must know that if the tanks rolled, or he threatened to make the tanks roll, Europe and the US would cave on Ukraine - he's got the political guts to frighten us, and we've not got the political guts - willingness - to stand up to him. he is, to some degree, a paper tiger - he could never win an actual war with Europe over Ukraine and his pockets aren't endless - but if he enemies run at the sight of a paper tiger, then he doesn't need to be able to win a military or economic confrontation...