Russia's military force in Crimea is actually pretty small. Perhaps 7,000 were sent in on top of 2,000 combat troops already in the 11,000-man garrison at Sevastopol. I have to ask if this is nearing the limit of what Russia can deploy in the way of reaonably good troops prepared to fight.
Despite Putin's attempt to make his military look awesome, his military really isn't prepared to fight more than a small war with any type of skill.
Oh, he could send large formations into battle. But they'd suffer heavier casualties against any decent opposition and would achieve their objectives only with brute force.
And when the basic load of fuel and ammo in his vehicles went black, the resupply effort might be less than impressive. Which is why I think Putin's window to easily seize eastern Ukraine is closing.
Any victory with this force would not be pretty. And when you fight a small power, you need all the style points you can accumulate to avoid looking like a bumbling giant that simply overwhelmed a tiny foe with no business even being on the same battlefield.
Remember, Russia did not take Tblisi in their short war with Georgia--a small country. And Putin appears to have wanted to do so.
But his military's performance could not have inspired confidence when the decision to go for total victory had to be made.
I lean to thinking that Putin didn't think his military could take the Georgian capital and emerge with their reputation intact as a major power's army. And I think this limitation continues despite high profile efforts by Putin to revive his country's military.
If so, this gives Ukraine more military options than just admitting defeat in Crimea and counting themselves lucky to escape without further losses.
It may be that Ukraine's military really is incapable of mounting an offensive even on their own territory against even a limited Russian force. But I don't think Russia's capacity to win a fight over Crimea is assured.
UPDATE: Really?
Russia already has massive assault forces in place, including:
810th Naval Infantry Brigade (Sevastopol, Crimean Oblast)
880th Separate Naval Infantry Battalion
881st Separate Assault Battalion
888st Separate Reconnaissance Battalion
1613th Separate Artillery Battery
1619th Separate Air-Defense Artillery Battery
Air-assault forces from Ulyanovsk and Ryazan have been flown to Sevastopol as well.
No, this is not a massive force. It seems to approximate the size of the ground force we sent to capture Grenada.
If your judgment that Russia has a massive force in Crimea means Ukraine stands no chance of fighting Russia, think again.