Combat ineffectiveness is a military term for when a unit has sustained sufficient losses to render it, ineffective. This is a general rule of thumb and greatly depends upon the ratio of frontline to support troops in the unit being looked at. Of major importance is the willpower of a unit to keep going. High morale and drive can keep a unit fighting longer than poorly organized units with low morale. These numbers are not prescriptive. There is no magic number for which when Russian casualties tick over it they suddenly all give up at once.
However, the math below is a way to guess how long Russia can sustain combat operations at their current rate of loss without replacement. I will use Ukrainian numbers for one extreme and Russian numbers for the other. The truth is probably somewhere in between. I will also use 33% casualties as the “target” for combat ineffectiveness. Russia has shown poor morale and logistics so that probably is a high number ( we have seen surrenders already).
For the first 4 days of conflict I saw one Ukrainian estimate for Russian losses at 4-5000 dead. We will use the 4,000 number. As of March 2nd I’ve seen a report that the US estimates 80% of Russia’s 190,000 troops near Ukraine have been committed, which makes for 152,000 troops in country. This make’s Russia’s casualty rate at 2.6% over 4 days time. At 1000 casualties per day, Russia will reach 33% theater-wide in 50 total days (so if we think 7 days in now, 42 more days or 6 weeks. That would be April 13th)
Using Russian numbers from the first 4 days we see a 1.3% casualty rate theater wide. At 500 casualties per day it would take 100 days (rounded) to make 33%.
There are a huge number of problems with this very basic analysis. Everything from variable rates of casualties to varying rates of effectiveness based on losses already taken which further changes casualty rates. It’s also impossible to predict how poor Russian logistics and morale can play into this as well. (But if the rate remains the same there will be no Russian troops in Ukraine in 150 days...). We also don’t know what rate Russia plans to reinforce.
Don’t take much from this. Except to say, neither rate seems very sustainable to me.