The US actively supported the opposition in order to overthrow the democratically-elected President of the Ukraine, Viktor Yanukovich. Victoria Nuland was caught on a tapped phone conversation discussing this. That is a direct violation of the Budapest Memorandum. All of Russia's actions have been a consequence of the undemocratic removal of a democratically elected leader.

As for the invasion of Iraq, while I supported it and still do, it is a situation where the US was protecting its national interest, just as Putin is doing in Crimea. As for Kosovo, that was just a gross abuse of US power based on Albanian propaganda - yes, there were some atrocities committed, but almost all of them were committed AFTER the US started bombing, not before. What happened before was an Islamist insurgency against Serbia that the Serbs were fighting. If I remember, other than Dinosaur McCain, almost everyone in the Republican Party was condemning President Clinton (and rightly so) for getting involved in Kosovo.

I don't think that we, or the Russians for that matter, should have to wait until our citizens are actually being killed to intervene to protect national interests. I repeat my question, which you can't seem to answer: why can Russia not act to defend its core national interests (naval base at Sevastopol) and its citizens (many in Crimea already have Russian passports), as well as people who are Russians but not citizens solely because they ended up on the wrong side of an arbitrary border in 1991?

As for Russians being threatened, it is happening. Western news media largely ignore it because it's inconvenient, but at least the BBC has been honest enough to report about it some. Listen to the conversation between the Estonian foreign minister and Catherine Ashton, which was tapped by unknown parties (probably Russia). They confirmed it's real. Not only does the Estonian foreign minister say that the snipers shooting at everyone all came from the same side, and the evidence is that they came from the side of the anti-government coalition (i.e., they were shooting their own people to get international sympathy), but he also confirms that Kiev is being run by armed mobs that are anti-Russian, that beat members of Parliament openly on the street in broad daylight because those people supported Yanukovich, and that the police are not functioning.

I'm linking a CNN article, but you can also skip right to the YouTube video here:

http://www.youtube.com/watch?v=ZEgJ0oo3OA8