Also - Putin's aims are to reinstate the buffer zones that the USSR negotiated at the end of WW2. That is a long-standing (ie before 1900) Russian aim*, along with achieving warm water harbours** in the Crimea and the Baltic. He is not interested in any conflict which does not achieve those aims, so his strategy is essentially to 'bite and hold' territory. That is what he did in the Crimea, what he is doing in Ukraine and what he will do next in Latvia, Estonia and Lithuania, which provide not only warm-water harbours but also a buffer zone in front of St Petersburg.
His aim is to preserve and promote Rusia, not destroy it, which would be the certain outcome of a general war, and would put his strategic aims back a century.
*The Central European Plain makes Russia very vulnerable to invasion (Napoleon, Hitler et al) and so Russia has always sought buffer states to protect their western flank. The eastern is protected by the
Urals.
** Russian ports such as Vladivostok and Archangel freeze in the winter. In order to maintain a naval presence Russia needs to have access to all-year ports and to be able to pass the Dardanelles. That latter might be tricky, so although Sevastapol is of key importance, Russia also needs a port in Syria (Tartus), which explains Putin's support of that regime, and passage of the Dardanelles which explians his warmth towards Turkey and the NATO/EU wish (what Cameron meant) to have Turkey in the fold.
https://www.airuniversity.af.edu/Portal ... hauhan.pdf
