>How much unrest in Ukraine will Putin allow before intervening?<
Ukraine is of a size of France and has a population figure only slightly shorter.
Thus they have sold their nukes and carriers to Russia in earlier 1990s, I think Ukrainian military is still the strongest in continental Europe.
It is not Georgia or Grenada.
Crunch time will come after the Olympics. Historically, countries have been on their best behavior when they hosted the games. All eyes should be on Russia/Ukraine after the Olympics end.