To answer your 3 paragraphs' 1.The west will sigh and moan about the Crimea, and do a bit of window dressing re sanctions but not much else. 2.Putin is loved and admired by most of his countrymen; he may well intervene in parts of Ukraine if Russian origin folk are threatened. 3. Unlikely he will go back to the others you mention. The west has no stomach or money for a military confrontation at the moment - we alone are reducing our army to 80,000 and the Germans are very reliant on Russian gas.