Let's look at things from a new, unusual perspective.
Saddam Hussein was a US protegè, until he started selling oil for Euros; the US$ was uneasy, and Iraq was delegitimized and Saddam "erased".
Muammar Qadafi was a soviet protegè, until he trained one terrorist too many, was bombed, and started playing nice guy.
But he too started selling oil for Euros, and the US$ was uneasy, and Lybia was delegitimized, and Qadafi "erased".
The United Arab Emirates, Kuwait, Qatar, Saudi Arabia are stinking rich with oil, but their human rights record stinks (only ones who still legalize human slavery)
and Islamic fundamentalism is actually funded by... you know...
So the US are uneasy, and someone might need to be... you know...

Then came Putin...
He too is selling natural gas to Europe for Euros, and the US aren't overwhelmingly happy.
The US tried plaing the "let's get the Ukraine to join NATO!" card, but it backfired.
The US backed Premier Yulia Timoshenko, an ethnic Ukrainian, and opposed Premier Viktor Yanukovich, an ethnic Russian.
What happened next were street protesters in numbers which varied and depended on nationality and political faction of the individual reporter.
I leave google surfing to you, but you understand what I mean: one man's million people is another man's 1000 stragglers...
Come the Crimea: the Crimea has been politically and ethnically russian ever since the 1st Crusade, and became Ukrainian only since 1917 to last month.
When the Ukraine petitioned the Soviet Government in Moscow for independence, one of the conditions was :
"OK, but the Soviet (russian) 5th Fleet gets to stay (in the Crimea)"
...because that's where it had always been ever since Czar Peter the Great, to battle against the very strong and expert Turkish Navy.
If Europe wag their "bad boy" finger at Putin, all he has to do is turn off the gas.
European reserves are good for 2-4 weeks, after which... never mind heating (it's april) but what about cooking ???

Here cometh the Goode Olde United States to the rescue, says you: WE will sell you our gas !

Across the ocean? Bottled, in ships?

It'll be much more expensive, but we'll have no choice... like comparing bottled water to tap water ...
So, it's a WIN-WIN situation (to the US) :
- you get to sell american natural gas to Europe, and make money,
- you steal more and more of the market share of fossil fuels from the Middle East, and make money,
- you sell armaments to European Nations who see the Middle East swaying under stronger and stronger fundamentalism... because they're getting poorer... and make even more money...
... and we get to fight a war we never even asked for...

... OR ...
Europe realizes that the Crimea is a Russian-Ukrainian problem, sees no reason to escalate, and see no reason why the US should raise such a hornet's nest,
when it was the US in the first place who insisted "we" should all internationally recognize Kosovo, or Croatia, or Slovenia, or Bosnia... as sovereign nations, independent from Yugoslavia...
...or why should Taiwan be independent from PRC...
...or why North and South Korea should not be united...
...and so on and so forth...
Regards,