Lessons from Finland for Ukraine and Its Foreign Legion

finnish sniper

Editor’s note: Don’t miss our comprehensive guide to Russia’s war against Ukraine.


On the heels of Russia’s invasion, Kyiv opened embassy hotlines and launched savvy websites to attract and funnel foreign volunteers into Ukraine’s fight for its survival. In recruiting legionnaires — noncitizens or foreigners who join another state’s military — Ukraine is embracing a military tool that has long shaped history’s major wars.

Legionnaires are attractive in no small part because the governments that recruit them can deploy and control them directly. Unlike mercenaries or contractors, legionnaires are enlistees in a state’s own military and follow the chain of command. And unlike foreign fighters — a term best reserved for those who join independence movements or rebel and terrorist groups — legionnaires fight on a government’s behalf and with the legal status afforded to citizen-soldiers.



Although research on foreign legions and the states that recruit them is still growing, recent history suggests lessons and insights that seem tailor-made to inform Ukraine and those following its conflict closely. In particular, Finland’s use of legionnaires during the Winter War suggests how these volunteers not only provide a boost to the combat effort, but can also serve to rally the international community.

An Oft-Used Tool to Stave Off Military Defeat

Kyiv is far from unique in turning to legionnaires in its darkest hours. In fact, most modern states have recruited them at one time or another. These policies have only grown more common since the end of the Cold War. Today, over 30 states include legionnaires in their armed forces. They populate the militaries of democracies and autocracies alike — from Australia, India, the United Kingdom, and the United States to Chad, Iran, Russia, and Saudi Arabia. Why do some states recruit legionnaires and not others? My research shows governments often open their militaries to legionnaires in one of two situations — in both, their goal is to stave off military defeat.

In one camp, governments recruit foreigners when they are trying to balance between domestic politics that make mobilizing citizens risky on one hand, and ongoing wars that necessitate the military secure more manpower on the other. Efforts by the United States to recruit foreigners during the Civil War or world wars, among others, were instituted for these reasons. Across history, similar motives have spurred democracies like India and Canada, and dictatorships like Nazi Germany and Fascist Italy, to enlist legionnaires.

But there is also a second camp of states that recruit legionnaires — those that, like Ukraine today, are battling for their very national survival. When a government faces the prospect of annexation or total conquest, it surges every possible kind of soldier into battle — including foreigners. For states facing an existential threat, the consequences of a military loss are simply so severe that leaders become willing to try even out-of-the-box policies to stave off defeat, including bringing noncitizens into battle.

But when states put these policies into place, how do they fare, and what do those conflicts tell us?

Finland Once Traveled the Path Ukraine Is Walking

The receiving of a Russian offensive and of an expansionist-minded leader in the Kremlin is an unhappy place to be. One story of resistance offers insights for how Ukraine’s recruitment could pan out, challenges and silver linings it may face, and how the conflict could unfold.

In November 1939, Finland found itself as Ukraine does today. After pressure from the Soviet Union to make territorial exchanges — ostensibly, as Moscow claimed, for Leningrad’s protection — Helsinki declined and the Red Army invaded. Like Ukraine so far, Finland had no allies willing to intervene directly and militarily. Determined to resist Moscow’s pressure and fearful that Soviet demands would only grow, Helsinki mounted a massive citizen defense, buttressed by active-duty troops and reservists seasoned by the country’s recent civil war — and, like Ukraine, foreign legionnaires.

By the war’s end in March 1940, Finland fielded more than 12,000 legionnaires — representing volunteers from Denmark, Hungary, Norway, and Sweden, as well as volunteers from elsewhere in Europe. Finland’s legionnaires occupied an array of roles, with some deployed alongside Finnish troops and others grouped into stand-alone companies and battalions with their co-nationals. Swedish personnel — including ultimately the famed Swedish Volunteer Corps — had some of the widest responsibilities on the front lines, and also lent expertise and equipment to provide air defense over northern Finland. Norwegians and other Europeans provided medical personnel to treat the combat wounded and civilians.

Beyond ground troops deployed against the Red Army advance, foreign volunteers also served as fighter pilots who helped blunt Soviet air power — a key form of support given Finnish pilots often faced Soviet formations ten or more times greater in size. In particular, Danish, Hungarian, Swedish and other European pilots shot down multiple Soviet aircraft, but at the price of severe losses. Beyond combat and combat support roles, legionnaires — particularly from Sweden and the United States — featured heavily in pro-Finnish propaganda used to garner international attention and sympathy.

While Finland certainly lost both the Winter War and the Continuation War that followed, it did escape the worst outcome Joseph Stalin had planned once he decided to invade — reabsorption of the country into Russia, or the installation of a pro-Moscow puppet government. Outnumbered by the Red Army and nearing exhaustion, Finland was forced to accept negotiated terms imposed by Moscow, ceding roughly ten percent of its territory to the Soviet Union.

Lessons from Finland’s Legionnaire Effort for Ukraine

For Kyiv, Finland’s wartime experience and legionnaire use suggest cause for optimism and caution alike. A review of Helsinki’s policies suggests lessons that, if properly implemented, could enable Kyiv to avoid the missteps that constrained Finland’s ability to maximize its legionnaires’ utility on the battlefield.

First, the logistical challenges of ferrying foreign volunteers to the Finnish front were a major — perhaps the major — hurdle in amassing volunteers. While the quality of troops assuredly matters, Moscow was able to deploy more than twice the number of troops — over half a million — than Finland was during the war. Beyond the sheer size of the manpower gap, Finland’s ability to maximize its foreign volunteers stumbled due to the intransigence — and outright opposition — of key regional states. For instance, Nazi Germany during the Winter War blocked would-be recruits from transiting to Finland through its territory, causing significant delays as volunteers took circuitous routes to the front. For Ukraine, Finland’s experience underscores that maintaining good ties and communication with its neighbors seems essential to the success of its legionnaire enlistment.

Second, Finland’s experience underscores the importance of careful vetting and a deliberate, organized approach to fielding foreign volunteers. Finland, and the supportive regional governments it partnered with, worked strenuously to ensure that its legionnaires represented dedicated, seasoned military professionals. Given a stark shortage of arms and ammunition at the war’s outset, Finland needed legionnaire recruits that it could field on the ground or in the air without diverting equipment from its own outmatched citizen troops. The selection standards that Ukraine is seeking to maintain — such as requiring applicants to participate in screening interviews, prioritizing individuals with prior military and medical experience, requiring recruits to sign a contract, and evaluating volunteers’ skills in person before assigning them to a unit — seems well positioned to ensure Kyiv can field combat-ready personnel as swiftly as it can put them into uniform.

Third, at the same time, Finland’s experience emphasizes that legionnaire-recruiting states — especially those facing a far larger foe — ought to plan for the future with the same care as they do in answering their immediate manpower needs and priorities. Numbers were always going to be Finland’s Achilles heel. While the emphasis on enlisting veterans had the benefit of ensuring the country’s foreign legionnaires were of high quality, it also meant Helsinki turned down tens of thousands of eager volunteers it could have used to fill understrength units sapped by later casualties.

By early 1940, as Finland’s own casualties grew and Soviet authorities surged more troops to the front, the issue of numbers reared its head once again. But in focusing — for good reason— on high-quality recruits, Finland was slow to capitalize on the enthusiasm of non-veteran volunteers, and to ensure it could shape and harness their desire to fight for the months to come. Helsinki did not begin relaxing its strict selection criteria for foreigners until January 1940, and its first training camps for non-veterans were likewise established at this time. Not until days before the war ended did Finland establish administrative and headquarters facilities to manage volunteers. While Ukraine may not be as severely outnumbered as its Scandinavian counterpart, Finland’s experience affirms what military support and logistics specialists know to be true: The most prudent time to start planning for the long haul is now.

Finally, the Winter War underscores how legionnaires can be valuable in ways that do not involve combat. The participation of legionnaires during the Winter War stoked and helped harness broad international opinion in Helsinki’s favor, ultimately easing Finland’s access to essential supplies. Like Ukraine, the global community held Moscow at fault for instigating the Winter War. Combined with the participation of international volunteers, the image of a valiant but outmatched Finnish military squaring off against the Red Army helped rally international aid to Helsinki’s cause. While this assistance began in the form of community-collections and charitable drives — much like the “hacker army” and civilian donations aiding Ukraine — public sympathy for Finland’s cause ultimately helped pressure European governments to lend their aid as well, albeit late in the game. France, Great Britain, Hungary, Sweden, and the United States ultimately sent a combination of aircraft, ammunition, and other supplies to aid the Finnish defense.

At 20,000 volunteers and counting, Ukraine in two weeks has achieved truly impressive results from its efforts to raise the globe’s newest foreign legion. Beyond the combat experience and specialized training its foreign recruits stand to provide — and in some cases, are already providing — Kyiv is also working to translate worldwide public sympathy into wide military support from the United States and its allies. With stories of U.S. and European legionnaires a recurrent feature of the news cycle, Ukraine’s president has a ready chord to play in attempting to sway domestic U.S. and European audiences to provide greater support. Even if his efforts fall short of the direct military intervention he has sought, his efforts to internationalize Ukraine’s fight for survival have already successfully secured hundreds of millions of dollars in promised financial aid as well as light and heavy weapons worth a similar sum

Although hopes for ongoing negotiations continue to swirl, Kyiv in the meantime is determined to do all that it can to ensure Ukraine’s survival. In levying legionnaires to the nation’s defense, Ukraine would do well to study the successes and missteps of its neighbor for lessons on how to best harness its foreign volunteers to weather Russia’s continued onslaught.



Elizabeth M.F. Grasmeder is a foreign-policy analyst in the U.S. government and adjunct professor of national security policy at Duke University. She has published on foreign legions and legionnaires in International Security and the Washington Post and is writing a book on why modern governments recruit foreign soldiers. The views expressed here are her own and do not reflect the official position of the U.S. government.

Image: Defense Department (Courtesy of Jere Paldanius, Finnish Defence Forces)