Could Russia Occupy Ukraine?

A Russian invasion of mainland Ukraine continues to worry Ukrainian and Western policymakers, despite statements by Russian President Vladimir Putin and Foreign Minister Sergei Lavrov that Moscow has no such intentions. The illegal occupation of Crimea serves as one source of disbelief in Russian sincerity; a second source is Moscow’s refusal to recognize the Ukrainian government or the forthcoming May 25th presidential elections. A third is the continued placement of Russian troops along Ukraine’s borders. Estimates of their number have ranged widely, from 30,000 to 220,000, with most falling in the 50,000–80,000 range. (On April 4th, however, Ukraine’s first vice prime minister stated there were 10,000–15,000 Russian troops along Ukraine’s borders and another 22,000 in Crimea.)

Ukrainian policymakers are right to assume that Putin’s intentions are not benign. That said, could Russia actually occupy Ukraine? How many troops would Russia need to hold Ukraine—especially under conditions of a Ukrainian insurgency?

A 2008 study (pdf) by US Army Major Glenn E. Kozelka provides some tentative answers. According to Kozelka:

To determine a historical gauge for planning force levels in a COIN [counterinsurgency] environment, this study provides a quantitative and qualitative analysis of two successful COIN case studies, the British-led Malaya Emergency and the US-led Operation in Iraq. Quantitative analysis of the case studies is used to compare the security force size employed to the population size…. Although each situation is unique and a fixed ratio will not guarantee success, there is a strong correlative relationship between force levels and success…. The case studies show that the closer force levels approach the ratio of 20 security forces per 1,000 population, the greater the possibility the COIN force will reach the tipping point to success.

Kozelka also cites a 1995 RAND Corporation study by James Quinlivan who “promulgates a continuum of force density levels, based on three levels of violence or threat intensity.”

Low violence (police operations): 1–4 security forces per 1,000 of population

Medium violence (civil unrest): 5–10 security forces per 1,000 of population

High violence (insurgency): 10+ security forces per 1,000 of population

Kozelka emphasizes that many local demographic, geographic, political, cultural, and economic factors can affect these numbers. They should therefore be viewed as general indicators, and not as precise measures.

I’ve combined Kozelka’s numbers with Quinlivan’s to produce a rough estimate of how many troops Russia would need to occupy Ukraine. Since the quality and counterinsurgency experience of Russian troops are probably much lower than those of British and American forces, I’ve used the high-range estimates: Quinlivan’s 4 per 1,000 in conditions of low violence, Quinlivan’s 10 per 1,000 in conditions of medium violence, and Kozelka’s 20 per 1,000 in conditions of high violence. I’ve also provided calculations for three clusters of Ukrainian provinces: low, medium, and high violence for Donetsk and Luhansk, which are most pro-Russian, but which also have significant pro-Ukrainian support and may therefore be unpredictable; medium and high violence for the other five southeastern provinces—Kharkiv, Kherson, Mykolaiv, Odessa, and Zaporizhzhia—where civil unrest or insurgency, or both, is likely. And only high-violence estimates for the remaining provinces, where insurgency would be greatest. 

The results are not encouraging for proponents of a Russian invasion.

• In order to occupy Donetsk and Luhansk provinces alone, Russian would have to deploy somewhere between 26,702 and 133,514 troops.

• A “land bridge” from Crimea to Transnistria would mean occupying Kherson, Mykolaiv, and Odessa provinces—which would entail somewhere between 46,497 and 92,994 soldiers.

• Occupying all seven southeastern provinces would require between 118,536 (26,702 for Donetsk and Luhansk and 91,834 for the others) and 317,182 (133,514 for Donetsk and Luhansk and 183,668 for the others).

• If Russia decides to conquer all of Ukraine, it would need an additional 548,587 troops—for a grand total of 667,123 to 865,769 troops.

• Kyiv city and Kyiv Province alone would require 90,676 occupying soldiers.

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.