Agree on NATO as a vital player.
The drip feeding of sanctions gets you nowhere, people get used to them as they materialise over a long period and they learn to live with them and work around them, it needed to be a full blown slam dunk to coin the American phrase. The problem with that is the west were not willing to suffer the drop in living standards and fall back into recession they could have brought on. It takes a strong willed and firm leader to enforce them, something we all in the west lack with the spineless sycophants we have in power today.
Costs and benefits in a complex world.
Perhaps the sanctions will have somewhat of a creeping effect combined with domestic issues in Russia and so on? The Russian economy isn't doing too well at the moment. One question is whether Putin might attempt to deflect public attention from domestic to foreign issues to an even higher degree.