Estonia, Latvia, and Lithuania have historical traditions of partisan uprisings and protracted post-Second World War partisan resistance by ‘Forest Brothers’ against Soviet occupation dragged on into the early 1950s. Lithuanian resistance fighters rendered some districts of rural Lithuania largely ungovernable for several years after 1945. Even Soviet historiography, not always known for historical rectitude, includes many accounts of “red partisan” Soviet irregular forces operating in the Baltic states to harry the German occupiers and German occupation of the region required devoting significant effort to rural security and policing. The post-war anti-Soviet ‘Forest Brothers’ are integral to modern Baltic identity. (It should be noted that much of this article is potentially applicable to eastern Poland or Finland.)

In the early days of post-Soviet Baltic independence in the 1990s, the three countries had to build military forces out of nothing. For at least a decade the only real defence against Russian invasion would have been token resistance followed by some attempt at partisan resistance. The militaries gradually grew in size and modernity, the Baltic countries joined NATO, and NATO plans evolved to actually consider defence of the Baltic States as opposed to merely trying to recapture them in a protracted war. The partisan defence card subsequently got dealt further down in the deck, but all three countries now adopt a total defence strategy under which every inch will be defended.

All three Baltic states have robust defence volunteer agencies aligned with the military. Estonia has the Estonian Defence League with approximately 18,000 members, not including affiliated auxiliary units. Latvia has the Latvian National Guard with 10,000 members and additional affiliated units. Lithuanian forces include the National Defence Volunteers, with over 5,000 members. Lithuania also has an old organisation known as the Riflemen’s Union, which has official sanction and a paramilitary mission firmly founded in the traditions of the Forest Brother movement, with about 14,000 members. Interestingly, the Riflemen’s Union website also says it promotes civil resistance. It is widely expected that a number of Baltic residents above and beyond these official movements would likely also mount partisan resistance.

What is it that irregular defenders can do that would make a difference in the event of a Russian invasion and occupation of the Baltic states in the modern era? Does any of this make any sense in this day and age of large-scale use of drones?

One lesson from the Russian invasion of Ukraine in 2022 is that Russian forces soon lose momentum if things do not quickly follow their operational plan. Kyiv remained free because the operation came unstuck. There are many reasons why a plan can fall apart, but one big concept is entropy. Partisan resistance in the form of fractally dispersed attacks and interdiction of routes of advance can serve to inject entropy into the operational environment, thus increasing the likelihood that a coherent operational plan degrades and erodes. The advent of a belt of fortifications on the Baltic frontiers with Russia and Belarus can serve synergistically. This can buy needed hours for partisan resistance to disperse into forests and swamps. Local partisan fighters can take advantage of local zones of the defence line to harry the attackers more effectively or guide regular forces.

There are, potentially, more important aspects to partisan resistance in the Baltic states than the traditional sabotage, sniping and demolition. Making the occupation costly is an objective unto itself. By merely existing in a certain district or territory, it forces an occupying force to devote resources to securing everything that is a potential target. At points during the partisan war in the late 1940s, the Soviets needed to garrison twenty or more security force members for each actual partisan in a region – and that was at a point when the partisan movement was lethargic due to resources. Existence of partisans in occupied areas saps the morale of enemy troops. Troops with poor morale make more mistakes and surrender more often. The history of guerrilla and irregular warfare is replete with examples of relatively small forces making a large conventional force miserable by inflicting thousands of micro-scale acts that combine to make the occupier miserable. Making the occupation of Baltic territory as costly as possible can certainly be a part of a total territorial defence strategy.

Observers of the war in Ukraine are probably correct to think that many aspects of that war would be applicable in the Baltic states. Drones are likely to take on a big role. Drones and other forms of long-range lethality (and let us not forget that Estonian and Lithuania now have the High Mobility Artillery Rocket System (HIMARS) and Latvia receives them in 2027) need target acquisition to be used effectively. A dispersed legion of partisans in hiding is good for target acquisition on a large scale. While the joke is that there will be a rifle behind every tree, a pair of eyes behind every tree with communication capability will mean that no Russian movements or actions go unspotted. Other forms of intelligence collection will also likely be significant missions for partisans. Instead of going out in a blaze of glory in the first 12 hours of a Russian invasion, perhaps the most important way to help would be to melt into the forests and constantly feed information back to regular forces and their allies.

Are partisans themselves vulnerable to drones? Indeed, they are, and tactics will need to adjust for this. By definition, partisan warfare is usually marked by dispersal of forces. The Baltic countries learned in late 1945 that operating in platoon strength only elicited a strong response from the Soviets. The Russian army in the current era may end up expending individual drones chasing individual partisans in the forests and bogs in expensive attrition.

Drone warfare cuts both ways, but it also has a third aspect. Drones can make supporting partisan resistance easier. The post-Second World War partisans had no effective external support (a handful of Western intelligence service missions focused on infiltrating agents, not materiel), generally lacked high explosives for demolition, and were short of food, communications technology, weaponry, and ammunition. Small drones for delivery of crucial supplies can slip necessary supplies out to small partisan detachments and change the logistical dynamics.

There is also likely a psychological aspect to partisan resistance as part of a total defence strategy. National morale is important. The Ukrainian war has lasted longer than the First World War in large part because national morale has not collapsed. Part of total defence is knowing that every inch of the country is being fought over. Partisans take on a symbolic role as well as practical missions in such situations.

The Baltic countries are small. There will be no distant hinterland where people can go about their lives. Warfare will affect everyone from the first day. Everyday normal citizens are going to have to make incredible sacrifices, just like people in Ukraine have done. Partisan warfare will be part of it, even if not terribly successful in conventional terms.

Partisan warfare is a valid component of total defence strategies. It is only hinted at in current defence doctrine in the Baltic States, but there is force structure and willpower in place to make it happen. The people there will likely live up to their history.