The most important foreign policy initiative President Obama is trying to achieve against great odds is a nuclear agreement with Iran. Central to this is having credibility that any promises made regarding Iranian security if they do not pursue acquiring nuclear weapons (which I do not think they are currently doing) must be credible. It may be that he may have to engage in drastic action in the near future in order to maintain that credibility.
The New York Times top story today is that Russian troops are massing on the border of Eastern Ukraine, presumably threatening an invasion, either to carve off heavily ethnic Russian areas or to run all the way to Kyiv to reinstall former President Yanukovich, whom Putin claims was illegally an inappropriately removed from office. It may be that he is planning a strategy like that he pulled a few years ago in Georgia. How to get South Ossetia? Invade Georgia proper and whomp their military, after which everybody is relieved that they retreat while holding on to South Ossetia. Could be just the trick for pulling off the apparently impending annexation of Crimea after Saturday's referendum.
Now let me be clear. I think the case for Crimea to be a part of Russia rather than Ukraine is strong. Quite aside from the fact that probably a majority of the population prefer that outcome for this autonomous republic, it was a part of Russia prior to 60 years ago when Soviet Premier Nikita Khrushchev gave it to Ukraine on the 300th anniversary of the unification of Russia and Ukraine, he of of mixed ancestry, supposedly feeling guilty about his role in what went on in Ukraine in the 30s and egged on by his likely mistress and former Party leader in Crimea, Yekaterina Furtseva, who wanted to keep Tatars and Greeks and others from returning after being deported by Stalin in 1944. All that was part of an implicit deal: Ukraine would get Crimea but would remain part of the same nation as Russia, the Soviet Union. Probably Yeltsin should have insisted on the return of Crimea when the USSR broke up, but he did not do so. In any case, while it is hypocritically sneaky, one must recognize that Putin is maintaining a legal cover by asserting that all those pro-Russian militias running around in Crimea are really just local Crimeans rather than actual Russian military, even if we all know better. He is maintaining the facade of not invading Ukraine.
Here is why that is important, and why an outright invasion of the rest of Ukraine would be very bad news. In 1994, Ukraine had the third largest store of nuclear weapons in the world. It gave it up in an agreement signed by Russia, Ukraine, the US, and the UK, which I understand France and China also later signed on to, this agreement guaranteeing the territorial integrity of Ukraine in exchange for sending all those nukes to Russia. Russia is the last nation on the planet that should be violating this agreement, but this apparently what it may be about to do.
I hate to come on like this, I really do, but I am about to come on as more hawkish than John McCain, more so except for that nutcase wanting to put nukes on planes in Poland. Anyway, I think if Russia openly invades Ukraine proper, the appropriate response is not just economic sanctions, which Putin will simply laugh at. This is very dangerous, but Putin has clearly gone completely off the deep end of power mad egomania, surrounding himself by an inner circle of sycophants. For the future of any nuclear peace, he cannot be allowed to get away with violating this agreement.