Putin is taking the politically appropriate course of action from the Russian perspective. The question for him is...Given Ukraine's leaning to the European sphere,currently, will turning off the gas tap result in the Ukraine being MORE LIKELY or LESS LIKELY to favour european alliances in preference to those of the FSU? For Putin the resulting anger in Kiev etc will drive the Ukraine farther from Russian influence and deeper into the arms of western capitalism. For a completely unreconstructed soviet like Putin this would be a terrible disaster. If Gazprom fails him by not coming to an agreement with Ukraine how he punish THEM?