It is absolutely appropriate to condem Russian militarism in the Crimea. I recently did so on Russian TV and was yelled at for my trouble. But it must be noted that:
 
1. The United States promised Russia years ago that NATO would not expand "an inch" eastward (see account by President Ronald Reagan's ambassador to the USSR in the New York Times of April 20, 1999);

2. NATO has rapidly expanded eastward (having already added the Czech Republic, Hungary, Poland, Bulgaria, Estonia, Latvia, Lithuania, Romania, Slovakia, Slovenia, Albania, and Croatia);

3. The United States has invested $5 billion in shaping Ukrainian politics including overthrowing a democratically elected president in the Ukraine who refused to join NATO (U.S. Assistant Secretary of State Victoria Nuland is on video talking about the investment and on audiotape planning to install Ukraine's next leader who's now in place);

4. The refusal to join NATO was a democratic action as the people of the Ukraine oppose joining NATO according to numerous opinion polls;

5. The United States is now negotiating to fund the new Ukrainian government in exchange for placing missiles in the Ukraine (as recounted by the Ukrainian ambassador to Belarus); not to mention that

6. The new Ukrainian government (as widely reported) includes neo-Nazis openly hostile to Russia among other things. 

Columnists like Tom Friedman argue that we should avoid war but focus U.S. policy on frightening Russia. That's like trying to avoid a fire by playing with matches.  The United States ought to apologize for Afghanistan, Iraq, and Libya, stop threatening Syria and Iran, halt the drone strikes on Pakistan and Yemen, and get its own claws out of the Ukraine. THEN denouncing Russian aggression will carry the weight it ought to carry.
 http://warisacrime.org/content/putin-ruining-world