Let me add on the economic side, Russia does not have the economic might to do everything it does now. Its military expenditures have increased in real terms from 3.3% of GDP in 2008 to 5.3% of GDP in 2016, according to the Stockholm International Peace Research Institute, which offers the best statistics on military expenditures. That's an extra 2% of GDP each year devoted to his wars.
On top of that, as Ambassador Herbst mentioned in his initial statement, the cost of the financial sanctions according to the IMF is 1% to 1.5% of GDP each year. This is 3.5% of GDP; add a bit for the administration of Crimea and Donbass, and you're at 3.5% to 4% of GDP extra because of war and sanctions on Russia.
This means that Russia is doomed to stagnation as long as it performs this way. This is also the reason we are seeing Russia now doing, as Ambassador Herbst said, so much Gerasimov doctrine, hybrid warfare, because it's cheap. It's cheap to assassinate people, for example, and hybrid cyber is the cheapest way.
Therefore, we are seeing a different kind of warfare, but it also means that Russia does not have the economic strength to let the tanks roll into Ukraine.