Just read this line: "What's Happening In Crimea Would Be Like France Sending Troops To Quebec."
I think that's a tough analogy, since France doesn't border Quebec.
The analogy ppl keep coming to is Germany with Czechoslovakia in 1938.
The paranoia of any military crisis being the eve of the next Great War is embedded in the American psyche.
Except that in this case this is pretty much a description.
US has treaty obligations here. Either the invading Russian troops get bombed by US, UK (and, hopefully, the rest of the NATO troops), or US treaty obligations are not worth the paper they are written on. If US abandons Ukraine, Taiwan, South Korea and Japan might as well negotiate decent terms of joining China.
Some ridiculous percentage of treaties are ignored, when the time to enforce them occurs.
Also, didn't we also have some treaty with Georgia?
The only treaty that really matters to the United States is NATO. That's all.