The US ought to step back; take a deep breath, and back off all the grandstanding about protecting sovereign boundaries and obeying international law; neither of which is demonstrated by the way we behave when it comes to countries the US targets.
President Obama seems to be much less secure in his shoes than he likes to show or he is pandering to a bunch of "cowboys" (Bushies) that like to huff and puff about nothing reminiscent of other "tail wagging the dog" incidents of the past. This seems to be more about "egos" and the way the US is again unable to bring a country (Russia) into line when it comes to manipulating international affairs.
The Ukraine is a country in political turmoil and going through some tough times readjusting in relations to it's neighbors. The West (US included) has a vested interest in disrupting a government that they don't approve of as with Velenzuela, Eqypt, and others who lean towards a more socialistic/people oriented forms of government.
All Putin is doing is showing that 2 can play the same game and it looks like the US doesn't want to play.
The Administration could spend their time and energy on real breaches of sovereignty and violations of international laws like what's been going on for many years between Israel and Palestine.
Kerry: Russia faces isolation over ‘aggression’ in Ukraine