Following up on the weekend’s troubling events in Donetsk, Luhansk, and Kharkiv, Alexander Motyl calculates that Russia would need a large military force to occupy Eastern Ukraine, especially in the event of an insurgency:
In light of Russia’s estimated current force levels on Ukraine’s borders (50,000–80,000), the best Russia could do under low- and medium-violence assumptions would be to invade a few southeastern provinces. If those assumptions are changed to medium or high, only one or two provinces would be within its grasp. These conclusions assume that an invasion would entail no force deterioration as a result of the Ukrainian army’s resistance. Change that assumption, and Russia’s capacity to occupy southeastern Ukraine declines even more.
In sum, Kyiv is right to worry about an invasion of all or part of its southeast—but only if Russia makes optimistic assumptions about the extent of resistance. Accordingly, Ukraine’s immediate goal should be to strengthen its southeastern defenses—preferably with American help—so as to deter a focused attack or, at the very least, to make such an attack so costly as to raise the conditions of expected violence in individual provinces. (Ukraine’s medium-term priority should of course be to develop a full-scale defensive capacity.) But, unless Putin decides to deploy most of Russia’s armed forces (which number about 750,000) against Ukraine and thereby place all of Russia on a war footing, readying bomb shelters in Kyiv may not be a Ukrainian priority.
(Map from Max Fisher, who sees an invasion as more and more likely.)