Putin assumes that CIA agents were behind the ousting of his clients in Kiev last month. It is what he would have done in their shoes. You can almost see him beaming with (misguided) professional pride: a (highly visible) covert operation emphasizing (implausible) deniability by (inadequately) disguising invading Russian troops and then establishing a (puppet) Crimean regime to appeal for annexation.
This is skillful espionage work — by the standards of U.S. covert operations in Guatemala, Iran and elsewhere in the 1950s. That seems to be Putin’s chronological frame of operational reference, not the 19th century.
But in the process he has made the mistake of proclaiming what amounts to a Putin Doctrine: Moscow will intervene to protect ethnic Russians in other countries against even imaginary dangers. He updates the ideologically motivated Brezhnev Doctrine with obsolescent ethnic and nationalistic guidelines for intervention.
This is not where he intended to be a few months ago, when he was magnanimously releasing his arch foe Mikhail Khordorkovsky and the Pussy Riot dissidents and basking in the reflected glory of the Sochi Olympics. Then, he was working to bring Russia deeper into the international system, not plunge it into isolation.