I had already written on why Ukraine was so successful in its resistance to Russian invasion. Reasons are many, but here I will be addressing one reason in particular: usage of reservists and irregular units.

Ever since the end of the Cold War, NATO had been turning to a professional army model, under assumption that it is more effective and easier to deploy. But the professional army is essentially an offensive army: good for NATO’s imperial interventions, but not good for national defense or a protracted defensive war. Home Guard / territorial defense can be extremely effective for the purposes of home defense, and war in Ukraine is an excellent example.

In terms of regular military, Ukraine was massively outnumbered: 850 000 to 200 000 in active duty personnel, 2 million to 900 000 reserve duty personnel, 4 173 to 318 in aircraft, 605 to 38 in ships. Yet in terms of troops actually deployed, Ukraine has the advantage. This is mostly thanks to territorial units and reservists, which are providing a large number of highly motivated if not necessarily well trained troops.

But these figures are wrong. Reservists seen in the figures are most likely the formal reserve duty personnel of the army. But reserve merely includes people who had been in uniform in the last five years and are considered trained and available. Yet looking at the last similar conflict in Europe – the war in Yugoslavia, and specifically the Homeland War in Croatia – it was not only the Ministry of Defence forces that were crucial in defending the country. Special Police Forces of the Ministry of Interior, as well as private militia forces such as Croatian Defense Forces (HOS) raised by the Croatian Party of Rights had more than pulled their weight in defense of the country. Situation is same in the Ukraine, yet these forces are usually not included into various graphs comparing military strength.

It can also be seen how ability to mobilize large forces relative to population had significantly declined in comparison to the 20^th century conflicts. In 1913., Germany had 660 000 troops in uniform, but managed to mobilize 3 820 000 reservists in a matter of days once mobilization had started. This was done out of population of 68 million – combined force of 4 480 000 would represent 6,6% of total population of Germany. According to this, Ukraine – with 40 000 000 people – should have had a mobilized force of 2,64 million while Russia should be fielding 9,65 million troops. Yet forces available are less than half of this, and forces actually fighting in the field are smaller still.

USSR had a very good mobilization system and a large pool of trained manpower, which allowed the Red Army to survive the extreme losses of 1941. Germany and other Axis powers had no such system, limiting their ability to replace troops. This system was preserved throughout the Cold War, which caused NATO extreme paranoia about the possible invasion by the Red hordes. All the “bad” elements of the Soviet army – understrength units, bloated officer corps – were a consequence of this requirement, existing in order to preserve the capability for quick mobilization of large numbers of men.

But this system fell apart with the Soviet Union. While Russia still has a nominally large reserve, it is not actually capable of quickly calling it up and fielding it. The number of 2 million reservists is merely number of people who are liable to be called up, having served in the last five years. Actual reserve force is of unknown size, but certainly far smaller than that (possibly cca 100 000 men). Russia also cannot fully mobilize so long as it keeps insisting that it is not, in fact, fighting a war. And much of the equipment that had been preserved in storage is not actually usable any more as it had not been properly maintained. Russia is thus trying to fill in the lack of numbers by using paramilitary, mercenary and contractor units. These also include the Chechens, whose deployment had resulted in a comprehensive failure at best. Syrians had not been deployed to Ukraine, but the Wagner group of Kremlin “mercenaries” had been deployed although their combat performance against Western troops implies they will be worse than useless. Most of cannon fodder however is provided by the local proxies, with two “People’s Republics” having a combined strength of 34 000 men in uniform. These are definitely cannon fodder, being undertrained and underequipped compared to either Ukrainian or Russian forces.

Reservists and irregulars are not as capable as full-time professional soldiers in maneuver warfare, but they can be extremely capable of performing less technical defensive operations. And it is these groups which had given Ukraine a massive advantage. Unlike Russia, Ukraine had decided that this is in fact a war, and had mobilized its forces. These forces are highly diverse: reservists, territorial defense units, militia, irregulars, volunteers and foreigners. While it is a far cry from World War I organized effort, it has proven effective.

Territorial defense units in particular had proven far more effective than anyone in the West or in Russia had anticipated. They are not very mobile, and tend to be more lightly equipped than regular forces. As name suggests, main focus of the territorial defense is defending their own localities. These are primarily infantry forces, using small arms, ATGMs, RPGs and mortars. While not capable of mobile warfare, they had proven able to blunt, slow down or even completely stop offensives carried out by regular Russian Army units. They had also proven how useful simple technology – recoilless rifles and ATGMs – can be when defending, and in fact these tools were what enabled territorial units to be as effective as they had been. Territorial defense units, with their knowledge of local terrain, had also played a crucial role in cutting off Russian supplies by ambushing supply convoys. Activity of the territorial defense has enabled Ukrainian regulars to even launch offensive actions in places – and by “offensive”, I do not mean using harsh language.

It is also TDF that are often salvaging and even stealing Russian vehicles, which had been a massive help for Ukraine, especially in terms of logistics. Stiff defense of the few cities that Russians did attack as well as their decision to bypass most cities is also the result of presence and effectiveness of territorial defense units. But bypassing cities means that these territorial defense units can cut off Russian supply routes that pass near the cities. Russian proclivity towards mass artillery bombardments of cities may also be partly a result of TDF presence, as the Russians attempt to utilize firepower to either dislodge or even destroy TDF, or at least suppress them and deny them cover by leveling the city in question.

It is true that Territorial Defense units are not, pound for pound, equal to regular forces. They lack mobility, they lack firepower, and they also make some very elementary mistakes in their actions. But their sheer quantity, determination and knowledge of local terrain means that their overall impact is far greater than the West had expected, or been ready to admit. TDF had played a crucial role in many battles that had forced Russians to withdraw and abandon their attacks. And TDF is further stiffened by militias and irregulars, which are extremely effective in urban areas.

But the impact goes beyond just fighting forces. Many of the supporting roles that are normally performed by active-duty personnel had been taken over by the civilians, enabling a massive increase in the regular army’s tooth-to-tail ratio. And this does not include only obvious stuff such as cooking or building tank traps. Civilians had been recovering damaged equipment by using tractors – in one such case, recovering an armored recovery vehicle. Using tractors driven by civilians had massively increased Ukrainian army’s armored recovery capability. And of course, civilians taking photos had helped both intelligence gathering and information warfare.

This is also one of murkier elements of the war. These “civilians” are, essentially, performing military duties. By any stretch of logic, that should make them viable military targets – but humans aren’t exactly known for being logical beings, so Russians targeting Ukrainian civilians would be a major propaganda coup for Ukraine. Overall, Ukrainian mobilization had been remarkably effective, though official military forces had only doubled in size.

Reservists and militiamen are also performing humanitarian duties, delivering water, food and other supplies to civilians who had to remain in their basements within the combat zone. Territorial defense troops also act as intermediaries between the military command and civilian population, as well as between professional soldiers and civilians. This allows civilians to be both better protected and also better integrated into the defensive effort.

Question is whether this will reverse the trend in reduced role of reservists. Historically, part-time soldiers had been the primary numerical component of most states – whether we are talking about the medieval Europe, the Middle Byzantine Empire, medieval China or 20^th century Europe. Only after the Cold War did the active-duty, full-time professionals become predominant type of troops. Yet today, only United States and Switzerland are fielding very large number of reserve forces in the form of the US National Guard and Swiss militia system. Western militiaries are mostly designed for expeditionary warfare, which is to say aggression against other states, and so do not have very large reserve forces. Nor are all reserve forces equal: Ukrainian territorial defense units are a clear militia, while US National Guard are fundamentally part-time professional troops. Yet Ukraine (much like Croatia in 1990s) shows that a militiaman does not need to be equal replacement to an active-duty soldier: they just need to hold the ground while regular army units carry out maneuver warfare. It is entirely possible to “cut corners” while still having a very effective military force, at least for defensive warfare. But it is necessary to be able to contest air superiority in order to enable this, which means heavy investment in air defense systems and air force.

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