I don’t recall the exact definition, but international law is what the various nations agree that it is. Russia at the present time is attempting to rewrite the rules. What the US does at this time, will probably determine what will happen in the next 50 years. Terrorism tends to pale into the background when one is dealing with a nation with nuclear tipped MIRVed ICBMs and an attitude. In addition, the Russians respect force. Words will not convince them. Words and actions might. IMHO Recall that the ChiComs, compliments of the Clintons, have, even as you read this, nuclear tipped ICBMs aimed at US cities. Voters on the west coast should think of this when they vote.
Historians have said we are in a new era when might doesn’t redraw maps as it has for the last 5,000 years. Putin’s Russia is just letting us know that the old rules still do apply.
Czar Putin is following Czarist objectives and trying to expand his rule. Ukraine better wake up. They have several choices A) Renew the Russian navy base lease and cut the best deal they can. B) Rearm as quickly as possible to hold this bit of land. C) Build up a fleet of their own. D) Become energy independent ASAP because the Russians will use oil and natural gas as a weapon. E) Join NATO ASAP and forge links to the USA and hope Obama doesn’t get elected.