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  • Writer's pictureDaniel Campbell

International Brigades: How the Ukraine Invasion brought back a Forgotten Tactic

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“If you had asked me why I had joined the militia I should have answered: 'To fight against Fascism,' and if you had asked me what I was fighting for, I should have answered: 'Common decency.” ― George Orwell, Homage to Catalonia, page 22

In Eastern Europe a small democratic nation fights against a major power led by an authoritarian dictator, with the intent to annex the smaller state under the pretext of protecting Russian citizens. You may think I just described the current war in Ukraine, but that was describing the Winter War of 1939-1940 between the Soviet Union and Finland. There are many parallels between Finland then and Ukraine today. For example, there has been a mass influx of foreigner volunteers seeking to fight for the smaller state in its David vs Goliath struggle. It begs the question: Why would someone with no ties to Ukraine wish to travel thousands of miles to fight against one of the largest militaries on the planet? Academic literature on this topic is still emerging, and thus the purpose of this article will not focus on the foreign volunteers themselves, but rather what their presence signifies. After all, this is the first time in over 70 years foreign volunteers have gathered on this scale to partake in an inter-state conflict. This has global ramifications, not only for the conduct of warfare, but also the geostrategic options available to states. By delving into historical parallels and legal loopholes, we can better understand how the scale and prominence of foreign volunteers will play a principle role in the major conflicts of the future.

History of Military Volunteerism

To avoid confusion, any mention of “foreign volunteers” will hereafter refer to non-citizens who are motivated by political or ideological reasons to willingly join a foreign army (Debora, C. 2022). This can include a sense of fraternity with “brother nations”, pan-nationalism, anti-authoritarianism, personal grievances, regaining national honour or a sense of adventure (Karvinen, K. 2021, p.1). This avoids including non-state actors like terrorist groups, private military companies or soldiers deployed by their governments to “volunteer” in conflicts. Those types of combatants will hereafter be referred to as “foreign fighters” (Malet, D. 2010, p.97). This is an important distinction as there has been mass use of foreign fighters amongst terrorist groups and other non-state actors, particularly in the Middle East, North and East Africa, for several decades now (Jacquet, G.E, 2022).

Historically the mobilisation of foreign fighters in armed conflicts has been used throughout antiquity (Misra, A. 2022). The Roman auxiliaries and foederati, the French Foreign Legion, the American Eagle Squadrons of WWII, the Irish Wild Geese, the Gurkha’s and the Chinese “volunteers” who fought in the Korean War. However, large scale mobilisation of foreign volunteers is quite rare. During the Spanish Civil War (1936-9) up to 40,000 volunteers joined the Republican International Brigades and during the Winter War (1939-40) over 11,000 foreigners joined the Finnish Army (Misra, A. 2022 & Karvinen, K. 2021, p.19).

The practice of foreigners traveling to join armed forces in conflicts abroad started to die out in the post-war years for a myriad of reasons: from the reduction in inter-state conflicts, Cold War tensions, decolonisation, risk of nuclear war and the smaller scale of most wars (Arielli, N., & Rodogno, D. 2016). Volunteering still took place, but to a lesser extent like in the Arab-Israeli war of 1948 (Arielli, N. 2014). International Brigades, regiments, and legions became increasingly rare. The Ukraine Conflict has changed all of that. For the first time in over 70 years, over 20,000 combat veterans from across the world are confirmed to have gathered to fight in Ukraine (Agence France-Presse, 2022). The scope of this mobilisation is to such a degree that entire foreign volunteer-only brigades have been founded, such as the Canadian-Ukrainian Brigade, Pahonia Regiment, Georgian Legion, Norman Brigade and Freedom of Russia Legion to name some examples.

What makes these volunteers different from previous International Brigades is a broader spectrum of ideologies and presence of veterans (Faber, S. 2022). Foreign volunteers in the past either had a common political/ideological background, as was the case for the International Brigades in Spain, or a general lack of military experience amongst volunteers, evident in both Spain and Finland (Ibid). This new method ensures a larger talent pool for the Foreign Legion, made up of veterans from across the political and geographical spectrum and thus a more effective type of International Brigade not prevalent in previous conflicts (Cancian, M.F. 2022).

Encouraging Volunteerism: Are States Encouraging Foreign Volunteers?

Both the Ukrainian and Russian governments have been encouraging the presence of foreigners in the conflict, and with good reason too. The use of foreign volunteers comes with huge advantages over using professional militaries, private military companies (PMC’s) or militias. First, it leads to an instant boost in manpower (Lambe, A. M. & Raeburn, F. 2022). The Ukrainian side have gone one step further, making prior military experience a major requirement in the enlistment process. Thus, the instant boost in manpower is doubly impactful since many of their volunteers have training and experience that even some professional soldiers lack, let alone local volunteers (Doctor, A.C. 2022). Second, it acts as a powerful propaganda tool (Cancian, M.F. 2022). International volunteers become enduring symbols of international solidarity and support. Thirdly, volunteers fill vital skills gaps (Lambe, A. M. & Raeburn, F. 2022). One of the biggest excuses made against delivering certain equipment to Ukraine is that it will take some time to train locals in the use of such systems. But if you have access to thousands of retired veterans familiar with such systems, training others to use this equipment becomes easier (Hollings, A. 2022). By extension they can introduce new tactics and train inexperienced local volunteers.

There are also major geostrategic benefits for using volunteers in foreign conflicts. Strategic ambiguity. Most governments are willing to send humanitarian or material assistance to conflict zones, sometimes both, but fall short of taking the step of deploying troops (Watkin, K. 2022). Afterall this would be akin to a declaration of war, something no third-party state is willing to do even against a non-nuclear power. This exact same conundrum occurred during the Winter War, despite great sympathy for the Finns within western governments and the public, no state was willing to fight the Soviets (Karvinen, K. 2021, p.17). With their governments refusing to act, over 11,000 non-Finns made the personal decision to travel to Finland and fight (Ibid, p.19).

So how does a government react when it’s citizens ignore a directive and fight in a foreign war? It doesn’t have to do anything! Under the Hague Convention of 1907 states do not hold responsibility for the individual actions of their citizens (Watkin, K. 2022). So even if their citizens fought on the frontlines, that state cannot be held to account for their actions and thus no retaliatory acts could be placed on them. But to show some attempt to remain neutral, states can, and have, placed limits on citizens travelling to conflict zones and warned against volunteering (Al-Kassim, M. 2022). Somewhat contradictory, in both the Winter War and the Ukraine Conflict governments have also “unofficially” encouraged their citizens to fight, or at the very least turned a blind eye (Lipin, M. 2022). An example of this would be the British Foreign Secretary, Liz Truss, saying it was “absolutely right” for British servicemembers to join the Ukrainian Foreign Legion, only to be contradicted by Defence Secretary, Ben Wallace, who stated “I think there are better ways for you to contribute to the security of Ukraine” (Harley, N. 2022). These contradictory statements by high-ranking British officials has allegedly led to much confusion amongst would-be volunteers, in some cases convincing current defence force personnel to abandon their posts and travel to Ukraine as they thought the comments gave permission for them to leave (Evans, A. 2022). This may have encouraged more Brits to volunteer than otherwise would have (McLaughlin, C. 2022). Thus, if states make contradictory statements in regards to volunteering, they can indirectly contribute more to the war effort without facing any consequences from the international community or belligerents.

Danger Close: Why Using Volunteers is Risky Business

There are major downsides of using volunteers too. As previously alluded to, a foreign volunteer who travels to a conflict zone poses a risk to themselves and their comrades if they do not have relevant language or tactical skills (Lambe, A. M. & Raeburn, F. 2022). After all, they will receive their orders in a local language and would be expected to carry them out. Without those skills they risk endangering their mission. There are ways around this, such as nation-specific or language-specific units such as the Canadian-Ukrainian Brigade, but communication between volunteer and non-volunteer units will still require a lingua franca (Ibid). There is also a problem with receiving local equipment systems that foreign volunteers are not used to. There are currently volunteers from dozens of countries fighting in Ukraine, most of which were trained using different weapons, radios, tactics, ammunition and helmets to name a few examples (Blackwell, T. 2022).

Legal ambiguity for foreign volunteers can be a blessing, but it can also be a curse. How are foreign volunteers supposed to be treated if they are captured? Is the belligerents willing to conduct a prisoner swap that includes foreign volunteers? Is there compensation for their families if they are killed? These questions are currently being tested in the case of captured British volunteer Aiden Aslin, captured by Russian forces in Mariupol (Malet, D. 2022 & Taylor, W and Lewis, L. 2022). He and other captured foreign volunteers are considered as “mercenaries” by Russian leadership, thus they lose legal protection provided by being a POW and can be tried under criminal charges (Watkin, K. 2022). At the time of writing this article, he and two other foreign volunteers have been sentenced to death by a Russian-backed court.

Foreign Volunteers in Future Conflicts

The presence of foreign volunteers in Ukraine is somewhat setting a precedent for the modern era. Yes, foreign volunteers were used throughout the Pre-WWII period but we are living in a different age. Globalisation, easy access to information, increased ease to travel and the rarity of inter-state conflicts all contribute to this new phenomenon (Jacquet, G.E. 2022). The current conflict is the first major conflict on European soil since WWII. Inter-state conflicts in other parts of the world, such as the African continent or the Middle East, have not received such a large trend of volunteerism[1]. Could Ukraine have changed all that?

It is important to remember that there are two key factors that have contributed to the high number of foreign volunteers in Ukraine in comparison to every other conflict since WWII. First, the Russian Invasion was completely lacking any reasonable causus belli (Chen, B. 2022). Just War Theory stipulates that a state can justify an offensive conflict under certain circumstances, such as pre-emptive strike, defending communities from genocide, protecting its own citizens or acting on territorial claims (Shapcott, R. in Baylis, J et al. 2014, p. 205-206). But even once it has such a justification, the state must take every peaceful measure possible to resolve the issue (Ibid). Russia failed to meet every criteria there is. Nearly every claim put forward by Russia justifying an attack lacked hard evidence, whether it be “de-nazifying” Ukraine, genocide against Russian-speakers, American chemical weapons facilities within Ukraine, a Ukrainian nuclear-weapons program, ascension to NATO or even “historical claims” over the country (Chen, B. 2022). It should also be noted that attempts made by the Ukrainian Government, as well as western governments like France and Germany, to bring about a peaceful resolution prior to February 24th were not received in good faith by the Russians. This became clear when Russia released a pre-recorded video of Putin announcing a “special military operation” to prevent Ukraine from joining NATO after Zelensky publicly stated that NATO membership for Ukraine would never occur (Foreign Policy, 2022). The unjustified nature of this conflict has undoubtedly contributed to the number of volunteers flooding into Ukraine. So too have the allegations of war crimes committed by Russian troops, repeating previous Russian atrocities in Chechnya, Georgia and Syria, which also likely played a part in the large pool of volunteers coming from those regions (Al-Kassim, M. 2022).

[1] This is referring only to foreign volunteers, as defined at the beginning of the article, and not foreign fighters. As defined earlier, those who volunteer to fight for terrorist organisations, rebel groups, militia’s or other non-state actors in a combat role are not considered foreign volunteers. Therefore, whilst there has been mass use of foreign fighters in these regions over the last few decades, that has not been replicated in foreign volunteering.

The second factor is Ukraine’s geopolitical proximity to the West and the reputation of Russia amongst Westerners. This includes central, eastern Europeans and the Baltic states. As previously mentioned, this is the first major conflict on European soil since WWII and its belligerents are the two largest nations in Europe. With its inception comes the end of the Pax Europaea, the relatively peaceful period following WWII where there were notably few inter-state wars fought between those in Europe particularly those in the EU or NATO (Ó Beacháin, D. Dempsey, J. &Tonra, B. 2022). This afront to the status quo has angered European states, including previously neutral states like Switzerland, Sweden and Finland (Kizilaslan, M.A. 2022). The proximity to and affinity for Ukraine and the rest of the continent has been a major contributor in the amount of support given, particularly from central and eastern European states which experienced Soviet occupation and proxy regimes (Buchholz, K. 2022). The fact that Ukraine is a more democratic state following the 2014 Euromaidan Revolution also plays a role, since it builds a narrative of the conflict as a fight between democracy and autocracy (Al-Kassim, M. 2022).

These factors make judging the presence of foreign volunteers in future armed conflicts challenging, partly because this conflict is somewhat of an outlier in itself. But it does establish a precedent for what might happen in similar circumstances. Should China, for example, attempt to reunify with Taiwan through force, we can reasonably expect a similar wave of volunteering. That deployment may not see as many foreign volunteers, but the anti-authoritarian and pro-democratic sentiments of many volunteers in Ukraine does suggest a sizeable number would attempt to join in the event of a conflict (Faber, S. 2022 & Yip, H. 2022). Smaller-scale conflicts, on the other hand, are less likely to see large waves of foreign volunteerism. Whilst the growing prominence of foreigners in conflicts in the Middle East, West Africa and North Africa throughout the 2000’s and 2010’s may suggest there is a growing appetite for volunteering (Nir, A. 2018), the smaller scale nature of these conflicts prevented a mass mobilisation on a scale seen in Ukraine. That will most likely continue in smaller inter and intra-state conflicts taking place away from the Global North (Al-Kassim, M. 2022).

However, if a major conflict does break out, the recruitment standards put in place by Ukraine has set an example of how best to utilise foreign volunteers in modern warfare. Making little distinction between political ideologies for volunteers encourages more people to join International Brigades, but also helps to eliminate “politicisation” of conflicts as between states with different political ideologies (Faber, S. 2022). Placing heavy importance on prior military experience also increases the professionalism of International Brigades, allowing for them to be used more effectively on the battlefield (Cancian, M.F. 2022). Both these things also increase manpower reserves. That being said, the International Legion for Territorial Defence of Ukraine has made some major organisational mistakes, to the detriment of foreign volunteers serving under it, but which can be used to inform similar groupings in future conflicts. Foreigners who have returned from Ukraine report negligible support from Ukrainian authorities, lack of supplies, equipment, poor operational security, poor intelligence sharing and allegations of using international volunteers as “cannon-fodder” (Newman, C. 2022).

Moreover, in the event of another war states now have a means to influence the conflict without engaging in it or suffering backlash from rivals. Governments that allow their citizenry to volunteer in foreign conflicts can weaken their geopolitical opponents without actively opposing them. It provides a similar excuse often cited when PMC’s are deployed to foreign conflicts: They are acting on their own initiative, without the support of their governments (Brimelow, B. 2018). This is what already happens with organisations like the Wagner Group, which has recently operated in West Africa to facilitate Russian geostrategic interests there, but the Russian Government itself denies any connection to the group (Baker, N. & Zengerer, C. 2022).

The main take away from this development is this: The Ukraine conflict has provided a modern precedent for the mass mobilisation of foreign volunteers in major conflicts. This practice is likely to be repeated in future major conflicts, particularly if they are between democracies and autocracies and if they are of major global geopolitical consequence. Smaller conflicts, or those in the Global South are less likely to see a similar mass mobilisation, though foreign volunteers will no doubt still be involved. However, it does provide a blueprint for the organisation of foreign volunteer regiments. Volunteerism also provides a valuable political tool to combat rival powers whilst avoiding repercussions. This unique trend, as observed in Ukraine, provides benefits and challenges for the rules based international order, potentially ushering in a new, more globalised, age of warfare!


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