https://www.realcleardefense.com/art...te_820732.html
Updated: Russian Occupation of Ukraine Troop-to-Task Estimate
                                                          
                                                                By                                                   
Ben Connable                                                                                       
March 09, 2022             
                                                                                                                                                                                                                                                                                                                                                        
                                                                                                                                    <img alt="Updated: Russian Occupation of Ukraine Troop-to-Task Estimate">                                                                       (AP Photo/Vadim Ghirda)
                             
In early February, I published a detailed 
forecast  estimating the number of troops the Russians would have to deploy to  successfully occupy part of Ukraine. In my notional scenario, I assumed  the Russians would only advance as far as Kharkiv and the lower Dnieper  river. Using military troop-to-task analysis, I estimated Russia would  have to deploy 83,000 troops to secure that part of Ukraine and keep  another 83,000 in constant rotation for a total of about 160,000 troops.  That is just under half of the entire Russian army (the Russian Ground  Force). In this article, I update the occupation troop-to-task  assessment, accounting for President Putin's more ambitious invasion  through Kyiv in the north and Odessa in the south.
 This updated estimate is based on what I perceive to be four  bare-minimum tasks the Russians will need to perform: (1) secure the  perimeter of their occupied area from infiltration; (2) secure key nodes  like power stations and communications centers in urban areas; (3)  secure key roads and railways to keep open interior lines of  communication; and (4) secure the population and conduct civil-military  and counterinsurgency operations. Using a new, probable limit of advance  just west of the Dnieper River and north of Odessa, I estimate that the  Russians would need to deploy 
168,000 occupation troops and keep another 168,000 in constant rotation for a total of 
336,000  troops. That constitutes over 95% of the entire Russian Ground Force of  approximately 350,000 personnel, not including available Russian  airborne, special operations, or National Guard troops.
 All estimates that follow are based on the troop-to-task baseline estimates 
here.  I used the same population data and other cited sources to build the  present estimate. As I did in the first estimate, I used Google Earth  Pro for all linear and area calculations. All caveats that applied to  the first article apply to this article. Estimating troop-to-task is an  informed subjective activity. Numbers presented here are estimates only  and should not be used for military planning purposes.
 
Task 1: Secure the Perimeter of the Occupied Territory
 In the likely event that the Russians defeat the Ukrainian defenders,  the war probably will not end. Ukrainians probably will continue to  fight as insurgents against the Russian occupiers. As of early March  2022, hundreds of millions of dollars in Western military equipment are  flowing into Western Ukraine and into the combat zone. During an  occupation, these contributions likely will continue in support of an  insurgency. Russia will be forced to secure the perimeter of the  occupied territory to try to prevent infiltrations and protect their  occupying army. Figure 1, below, shows the estimated occupied territory  and the perimeter.
  
  
 Figure 1: Securing the 2,950-Kilometer Linear Perimeter
 Ben Connable
 
 From the Belarusian border north of Kyiv to the Russian border east  of Mariupol, the perimeter of the estimated occupied territory is  approximately 2,950 kilometers in length. Using the baseline calculation  of one battalion of approximately 540 troops to secure each  80-kilometer section, perimeter security would require 19,980 (rounded  up to +20,000) front-line troops. Because these troops need staff and  logistics support, this amounts to two reinforced Russian divisions with  2,400 staff, logistics, and aviation troops each (+ 4,800) and expanded  coastal security (+1,500 troops) plus an army headquarters (1,000) for a  Task 1 
subtotal of 27,300.
 
Task 2: Secure Key Nodes in Urban Areas
 If the Russians intend to hold or even annex the territory they will  have seized, they will eventually need to provide food, water, power,  sanitation, healthcare, and other essential services. Insurgents will  seek to target some of this infrastructure to undermine the occupation.  There may be approximately 26 million people living in this occupied  zone. Given the uncertainty of Ukrainian population estimates,  population displacement from the war, and the relatively stable  situation in Crimea (~2 million people), I use 19 million as a round  population estimate. There are 22 major urban areas in the occupied  zone.
  Figure 2, below, shows the urban areas requiring key node security.  Major urban areas like Kyiv, Kharkiv, and Odessa will probably have more  than five key nodes, so this should be considered a low estimate.
   
  
 Figure 2:Securing Key Nodes in Urban Areas
 Ben Connable
 
  In the original troop-to-task analysis I estimated that each urban  area would have five key nodes requiring security, that each node would  require 145 troops, and that every three nodes would require another 140  troops. 
Therefore, key node security would require 
25,900  troops (22 nodes x 5 nodes = 110, 110 x 145 troops = 15,950 + 5,180  staff = 21,130 + 4,800 division staff and attachments = 25,900, rounded  down). The running occupation subtotal for Tasks 1 and 2 is 
53,200 (27,300 + 25,900 = 53,200).
 
 
Task 3: Secure Key Roads and Railways
 Keeping an occupation force fueled, fed, and supplied with ammunition  and spare parts for vehicles, radios, and other equipment requires  freedom of movement throughout the occupied area. Ukrainian insurgents  will probably work to disrupt logistics traffic, ambush convoys, plant  mines and other explosive devices, and otherwise disrupt Russian freedom  of movement. Securing lines of communication requires setting up  checkpoints and running patrols along the routes most often used by  occupying forces. Some risk must be taken on secondary roads, all of  which can be used by insurgents to infiltrate and conduct attacks.
 Figure 3, below, shows the 7,255 kilometers of secured road and  railway in dark green, as well as a number of unsecured secondary roads  located throughout the occupied territory.
  
  
 Figure 3: Securing Road and Railway in the Occupied Territory
 Ben Connable
 
 I estimated that each 40-kilometer section of secured road and rail  would require 63 Russian troops, the equivalent of two platoons or a  reduced company. Working from a map analysis of the occupied territory, I  estimated the Russians would need to secure 7,255 kilometers of road  and railway. This breaks down into 181 sections, 63 troops per section  (+11,403), with 140 battalion staff for every 400 troops (+4,060), plus  two division staffs and attachments (+4,800) for 
20,300 troops, rounded up. The running occupation subtotal for Tasks 1, 2, and 3 is 
73,500 (27,300 + 25,900 + 20,300 = 73,500).
 
Task 4: Secure the Population and Conduct Counterinsurgency
 If Russia’s invasion succeeds, the Russian Federation will assume de  facto responsibility for the well-being of approximately 19 million  people. That is equivalent to the population of the American states of  New York or Florida. It is also approximately 14% of the current  estimated population of 
Russia. In terms of landmass and population, this will be by far the 
largest  occupation attempted by the Soviet Union or the Russian Federation  since the Soviet occupation of Eastern Europe in the years after World  War II. Much of the infrastructure needed to sustain the Ukrainian  population in the occupied zone is presently being destroyed. Occupation  officers will find themselves responsible for supporting millions of  people and rebuilding their cities while fending off an active,  NATO-backed insurgency. A dedicated joint civil-military and  counterinsurgency force will be needed to give the Russians any hope of  successfully managing these tasks.
 Figure 4, below, shows the Ukrainian State Statistics Committee  estimated populations for each Ukrainian oblast, or state, within the  occupied territory.
  
  
 Figure 4: Estimated Population Within the Occupied Territory by Oblast
 Ben Connable
 
 In the original troop-to-task estimate, I used the population  estimate for Kharkiv oblast as a baseline for analysis. I separated  Kharkiv into 10 sections of approximately 173,000 people each and  identified the need for a reinforced Russian motorized infantry  battalion of 650 soldiers to secure each section. Using this same  baseline estimate, Russia would need to assign 110 battalions (+ 71,500  troops) within eight divisions (+ 22,400 division staff and attachments)  and one army group (+1,000) for a total of 
94,900 troops. Total occupation troop cost for all four tasks is 
168,000  (27,300 + 25,900 + 20,300 + 94,900 = 168,400, rounded down). Another  168,000 troops would need to be kept in constant rotation for occupation  duty, tying down approximately 
336,000 Russian troops for what may be a multi-year occupation.
  If this occupation troop to task estimate seems high, points of  comparison might be useful. When the Soviet Union began its unsuccessful  
occupation of Afghanistan in 1979, Afghanistan had a population of approximately 13 million 
people. At the peak of its counterinsurgency operation, the Soviets had approximately 
100,000  troops in Afghanistan supported by an equivalent number of Afghan  troops and militiamen. At the end of 2011, two years before the Islamic  State seized one-third of the country, the U.S.-led coalition, and the  Iraqi security forces fielded approximately 
750,000 troops and police to control approximately 30 million 
people. Applying the oft-referenced 2% troop-to-population 
ratio—an approach I advise 
against—suggests  the need for 380,000 troops in Ukraine with another 380,000 troops in  constant rotation for a total of 760,000 Russian occupation troops.
  
Russia’s Advantages and Disadvantages in Occupation
 Russia has at least two distinct advantages and faces at least seven  significant disadvantages in a prospective occupation. Proximity to the  Russian border and relatively flat terrain provide good access for  logistics and air support, and Russian intelligence officers have a good  understanding of Ukrainian language and culture. They will not face the  same cultural challenges the United States faced in Vietnam, Iraq, and  Afghanistan.
 However, Russia’s aggressive destruction of Ukraine’s infrastructure  will make the occupation costly and onerous. Based in part on this 
RAND  examination of insurgency dynamics, the Russians will also be  challenged by the existence of a large sanctuary in western Ukraine;  strong external support for the insurgency; the probable emergence of a  hybrid rural-urban insurgency (which are particularly difficult to dig  out); the probable lack of a legitimate partner government in Kyiv;  probable lack of any reliable partner security forces to defray the cost  of all of these occupation tasks; and, primarily, the very low  likelihood that the Russians will seek or be able to address the root  causes that will drive the insurgency. Russians destroying Ukraine today  are fueling the 
will to kill Russian soldiers tomorrow and for years to come.
  
Dr. Ben Connable is a senior nonresident fellow at the Atlantic Council and adjunct professor of security studies at Georgetown University.