In fact, he should care. The Russian economy will suffer because of it. Russian GDP had dropped 30% already. The Ruble is going down. Today, the Russian martkets lost >10% of value. The Russian economy cannot withstand occupation, sanctions and feeding hungry Crimeans and East Ukrainians (Russian-speaking population). It is similar to Georgia/Abhasia/Ossetia situation, only multiplied by a 100. Not all Russians agree with Putin on that. There were anti-war rallies in Moscow and St. Petersburg ruthlessly suppressed by the Police. Not all Russians want to fight Ukranians, who fought side by side with them against Hitler. Russia should not follow Zhirinovsky path to hell.
"Right, as the world goes, is only in question between equals in power, while the strong do what they can and the weak suffer what they must.
But, aren't war economies good economies.
Maybe that could be Putin's secondary reason for overtaking Crimea.
1. Annex Crimea
2. Stimulate faltering economy with a "war economy" mentality that might just come in handy should other countries decide to intervene with Crimea and other Putin actions.