The Russian invasion of Crimea was essentially a Spetsnaz operation that organized local pro-Russian militias, and is roughly analogous to our initial Afghanistan campaign that used special forces and CIA operatives to organize Afghans to defeat the Taliban. The Russian campaign differed in that the Ukrainian defenders did not actively resist the subliminal invasion, and so the kinetics were minimal.
It seems that the Russians got by with only about 10,000 good combat troops in Crimea, who were never actually needed but which could have sallied forth from Sevastopol base had the Ukrainians resisted more than passively.
And on the other side of eastern Ukraine, the Russians have apparently put together only 20,000 troops:
The White House cast doubt Friday on the Kremlin’s claims that thousands of troops massing on the border of southeastern Ukraine are merely involved in training exercises, deepening fears that Russian aggression will not end in Crimea. ...
At the Pentagon, senior officers and analysts said they were monitoring the Russian infantry, airborne, air defense and other reinforcements with growing alarm, uncertain of President Vladimir V. Putin’s ambitions.
Pentagon officials do not believe that a new Russian move into Ukraine is imminent. But one of their big worries is that American and NATO officials would have virtually no time to react if it did happen. All told, officials said, there are more than 20,000 troops near the border.
I made an admittedly WAG estimate that Russia could scrape together half of their good troops and add in the same number of Interior Ministry infantry to bolster an invasion.
Russia could add in whatever number of ill-trained troops they want from their total forces and reserves, but they would risk bad optics if sent into action and tested in actual operations.
But I assumed 15,000 troops for Crimea and 25,000 troops for eastern Ukraine. They'd be backed by 10,000 and 40,000, respectively, Interior Ministry infantry.
Actually, the 20,000 troops we are watching isn't far off from my pre-war assumption. But if Russia really could free up 50,000 troops, I'd have expected that the Russians would use more in the east of Ukraine as long as they got by with fewer in Crimea. Apparently not.
And is anyone counting the Interior Ministry forces that could be used?
But would this be enough to secure eastern Ukraine? That's a lot bigger than Crimea. And a lot less pro-Russian. And a lot less pro-secession even among those who are pro-Russian:
“As I see it, there are now two options for Ukraine: become a federation or completely disappear as a country,” says Sergei Buntovskiy, an activist from Russian Bloc, a pro-Moscow political party. “But dividing the country? No one wants this, the older generations or the younger ones. If a referendum were held today, I think only 30 percent of the population would agree to it.”
Russian troops would also not be as widely supported here as they were in Crimea, Mr. Buntovskiy said. “I think more than half of the population would be very scared by troops arriving in Donbass.”
“Crimea has a stronger history of the nationalist question than we do here,” said Ms. Zhemchuzhnykova, the pro-EU activist. “We are more mixed here because so many different Soviet people came here to work. That may save us from Russia trying to use ethnicity as a tool in this game.”
Russia can certainly claim to be responding to popular will. But can Putin manage the images that will defy that claim? And absent popular local support for Russian help, can Russia's invasion and occupation force hold what they can certainly march in to grab?
I may be disappointed that Ukraine has not resisted in Crimea (and I strongly suspect we pressured Ukraine not to resist, to our shame, if true). But there is no way Ukraine won't fight the Russians if they try to stage a coup in eastern Ukraine (and I'd reopent the Crimea front, too, if that happens).
It may change one day, but thus far Russian military power is mostly fear of their nuclear arsenal that deters resistance when Russia uses their limited conventional military power.
UPDATE: Seriously?
The (Russian) force that is at the Ukrainian border now to the east is very, very sizeable and very, very ready," NATO's Supreme Allied Commander Europe, U.S. Air Force General Philip Breedlove, told an event held by the German Marshall Fund think-tank. ...
"There is absolutely sufficient (Russian) force postured on the eastern border of Ukraine to run to Transdniestria if the decision was made to do that, and that is very worrisome," Breedlove said.
He might have wanted to consult with a ground force commander--any ground force commander--before he made that statement. Twenty thousand Russian troops just off the eastern border of Ukraine are not in any position to make the 800 kilometer march across Ukraine to seize Transdniestria.
If Russia wants to annex the area, they'll just airlift troops to reinforce their small existing force there.
Go here for more on Russia's armed forces and Ukraine.