Russia's invasion of Georgia in 2008 was under a pretext of protecting South Ossetia from a "Georgian invasion." Russia began moving troops to challenge and harass the Georgian military or Georgians in Ossetia. By August 7th, he got his wish. When Georgian troops prepared to combat Ossetian militia within their own borders, Putin sprung the trap and attacked.
The nine-day war humiliated Georgia, which was unprepared for a full Russian assault. NATO assisted with $1 billion in aid and former Eastern Bloc countries flew to Georgia to express support. Still, neither was enough to prevent Russia from wrenching South Ossetia and Abkhazia from sovereign Georgia and declaring them independent states.
Putin's gambit six years later is very similar and also counts on the West believing that we won't risk a war for territory he wants. Recent military moves seems to show that he is.