Ukraine is not NATO so we should only stick with our obligations to NATO countries. And getting involved with no-fly is also none of our business nor in our interest. Lets just hope that Putin is satisfied with Ukraine once he has taken Ukraine, otherwise if Putin moves onto the NATO nations then it is definitely positively WW3.
And believe me, despite the media love for covering and exploiting war, and some people around here believing they would thoroughly enjoy watching on TV the US involvment in a war, I will bet that within 24 hours of American boots hitting the ground that both the media and every American including those here on AnandTech would turn from our engagement into war to "how soon can we get the hell out of this war?"
Within 24 hours, the fun of war would turn into the horrors of war. Americans suddenly living daily, hourly with real threats of nuclear war, not to mention prices here at home skyrocketing into the stratosphere. Ask yourself, are you really ready and willing to pay $25 for a gallon of gas, or $15 for a loaf of bread?
The problem with young Americans, those under 40, is that they don't really know war. They only read about WW2, and Vietnam. The only real wars most Americans have experience with was the well scripted hi-def 1080p senior Bush war in Iraq, and the middle eastern wars where Americans were never exposed to the coffins of dead American troops returning home. War was made to look pretty like an PG rated Hollywood movie.
If we get involved with a war with Russia, i.e. WW3, then that will be quite different for everyone here at home. We've never witnessed masses of Americans fleeing and escaping US cities to evade war, or the drafting of American kids into fighting a war. Not lately, that is. Not since Nam.
9/11 may be the closest example of the horrors of war for most Americans, but imagine 9/11 multiplied by every major American city? Then, you're getting close to imagining.