Russian economy was wrecked ~10 years ago, when Putin decided to go full retard and expanded the petrostate economy. It lost it's footing during the 2008 the crisis, managed to recover slightly solely due to outrageous oil prices, and ground to a halt in 2013.
http://economic-research.bnpparibas.com/Views/DisplayPublication.aspx?type=document&IdPdf=21959
Granted the Ukrainian adventure helped, a little. A little of that was even sanctions. But the current Russian economic crisis is founded in early 2000s, and was inevitable by 2010 at latest. Without Ukraine it would happen a bit later and perhaps be a bit milder, but no more.
I think this is the primary reason for his Ukrainian adventure. It wasn't because Putin felt threatened from the outside, but because he was facing an internal revolt if Russia didn't have an outside enemy to rally against. Plus the crisis gave him ample room for propagandist excuses as to why the situation is going downhill so fast.
On the upside, due to sanctions, western businesses are now somewhat insulated from the full-blown depression Russia will suffer next year. They are unable to loan them money due to sanctions, so we can just sit back and wait. We'll loose some business with Russia, certainly, but that was running on borrowed time anyway. No reason to cry over it, it was great while it lasted, but now the easy times are over.
McHrozni