Did Ukraine send way more troops to fight in the east than I suspected?
Ukrainian forces fighting in eastern Ukraine (Donbas) against Russian sponsored troops and Russian regular forces consists of Ukrainian Army units and an even larger number of volunteer battalions. These volunteer units comprise about 20 percent of the 50,000 armed personnel Ukraine has sent to the Donbas.
I think it is safe to assume that this number refers to the total number rotated through the eastern front and not the strength maintained there, since the Ukrainian army is only about 60,000 strong (pre-war active duty). And I have noted that a unit usually stationed in Ukraine's west was identified as fighting in the east.
Further, the Ukrainians were doing well until the Russians intervened directly with relatively small numbers of regular mechanized forces. So there couldn't have been too many Ukrainians if they were overmatched by a small Russian mechanized force.
Nor would it have been safe to commit such a large number of Ukrainian troops so far east where they'd be vulnerable to a battle of annihilation if the Russians escalated to cut off the region with mechanized forces.
I don't understand how the volunteer units could be both an even larger portion of the Ukrainian force sent to fight in the east and be just 20% of the armed personnel sent to fight.
Strategypage outlines Ministry of Defense territorial defense battalions (24+ battalions); Ministry of Internal Affairs special purpose battalions used for garrison duty in liberated territory (31 formed); volunteer National Guard battalions (4 formed); and a small -"Right Sector" Ukrainian volunteer corps of no more than 500, who are the armed wing of the political force of the same name.
I imagine we are talking about fewer than 25,000 light infantry in these units. I have no idea if they are in "for the duration" or just for the tour of duty. I suspect the latter.
These units have been crucial in holding the east while the army was demoralized:
These volunteer units played major role at the beginning of the conflict when regular units were ineffective due very low morale. The regulars were inspired by the energy and success of the volunteer units and eventually matched the volunteers in morale and effectiveness.
It would be helpful to know how many troops were committed on a day-to-day basis to the east and what Ukraine's current ground forces are.
But they did okay, all things considered.