A small country on the edge of Europe faces a ruthless attack. It staves off the initial assault. With the help of a major outside power, it defends itself with some success. It attracts support from international celebrities and the media. Idealistic foreign volunteers join the fight. However, the small nation’s great power patron eventually loses interest, and the flow of desperately needed arms dries up. The country succumbs, its story cherished by those who believed in its cause. But over time, the price of walking away from the fight becomes clear as Europe enters a new era of conflict.

This was the story of the Spanish Republic from 1936 to 1939. While the end is not yet written, it could soon also be that of Ukraine. Although historical comparisons are never exact, there are enough similarities here to give one pause. 

If embattled Ukraine’s situation is analogous to that of Spain eighty-five years ago, then it is Vladimir Putin’s Russia that has assumed the role of not merely Francisco Franco’s rebels but, more importantly, that of Adolf Hitler’s Germany and Benito Mussolini’s Italy, whose support made Franco’s victory possible. Ironically, it is the United States and its NATO allies that have supplied the weapons and training that have allowed Ukraine to survive thus far, just as, at least for a time, the Soviet Union under Joseph Stalin did for the Spanish Republic.

First Crisis…

War came to both Spain and Ukraine following extended periods of instability. After the fall of the authoritarian nationalist dictatorship of Miguel Primo de Rivera, the Spanish Republic was established in 1931. Amid the global depression, it faced constant pressure from far-right forces, including elements of the military and the “Falange,” a political movement founded by Primo de Rivera’s sons, which took its inspiration from Mussolini’s fascist regime in Italy. The Republic had other issues, including ideological divisions among its supporters, separatism in the Basque and Catalan regions, and Spain’s long tradition of anarchism.

The lead-up to the war in Ukraine was similarly troubled. Independent, since the fall of the USSR in 1991, it struggled in the aftermath. When, in 2014, the corrupt pro-Russian regime of Viktor Yanukovych, who had opposed an accord with the European Union, was toppled after massive protests, Russian troops (in disguise) helped create separatist “republics” in eastern Ukraine. They then occupied the Crimean peninsula, the site of Russia’s massive naval base at Sevastopol.

…Then War

The Spanish Civil War began after political turbulence became acute when a leftist coalition was elected to lead the Republican government. In July 1936, a military uprising began. While not all of the armed forces supported it, and in many cases, armed workers snuffed it out, it was able to survive and gain significant territory when rebel troops based in Spanish Morocco were airlifted to the Spanish mainland in aircraft supplied by Hitler and Mussolini. 

While German and Italian aid to the rebels was a crucial element of the Spanish Civil War, it was, to a great extent, a war of Spaniards against Spaniards. By contrast, the current conflict in Ukraine is an outright foreign invasion—the only exception being the troops raised by the nominally independent separatist, Russian-speaking Donetsk and Luhansk “People’s Republics.” The current phase of the war began in February 2022 when a Russian tank column pushed towards Kyiv, seeking, in Putin’s words, “to demilitarize and denazify” Ukraine.

The Spanish Civil War began as an attempted coup d’etat, which failed when rebel units were unable to capture Madrid and other principal cities such as Barcelona, Valencia, and Bilbao. The rebels gained significant territory, including provincial capitals in conservative rural areas, particularly Castile and Andalusia, and held cities such as Burgos, Valladolid, and Cádiz. Following the early failed rebel effort to take Madrid, the fighting settled into a protracted struggle for territory reminiscent of the American Civil War.

Given that Russia was a foreign power, its effort to seize Ukraine’s capital in February 2022 cannot be described as an attempted coup d’etat (although it reportedly had friendly figures ready to take the reins of power once it had secured the city). Instead, it was an effort at a “coup de main” (blow of the hand), a swift attack relying on speed and surprise. However, the effort failed in the face of stubborn Ukrainian resistance, along with mistakes in Russia’s force structure and the low quality of its equipment and manpower. Russian forces and those from the Luhansk and Donetsk “republics” did better in the east, gaining additional territory and taking areas close to Kharkiv, from which they were ultimately ejected later in the war.

A Helping Hand from Abroad

The Spanish Republic and today’s Ukraine survived the initial blows against them thanks mainly to great power support. While the Republican government had been able to count on those elements of the Army that remained loyal to it, it would have been unable to match on its own both the material and human resources that Hitler and Mussolini provided the rebels, which included the “Condor Legion” German air unit as well as military advisors, and in the case of Italy, a massive commitment of 80,000 men, who participated in air and ground combat. 

The United States and European democracies proclaimed their neutrality. They declared an embargo on arms shipments to either side in Spain despite Germany and Italy’s evident opposition. The Republic, however, did have an essential foreign patron in Stalin, who provided vital equipment early on and sent military advisors (and even aircraft pilots and tank commanders) while also offering training back in the Soviet Union. 

Like 1930s Spain, today’s Ukraine benefited from crucial external assistance in its struggle. It started from a better position than the Spanish Republic. During the years following Russia’s seizure of eastern Ukraine, it had received significant training and equipment from the United States and its European and Canadian partners in NATO, allowing it to evade Russia’s initial assaults. This extensive aid (The United States alone gave close to $24 billion between 2021 and 2024) has continued until now, although as of the writing of this article, its future is uncertain.

Foreigners Embrace the Cause

The Spanish and Ukrainian conflicts are remarkable for quickly becoming international causes célèbres. In both Europe and the United States, extensive campaigns of sympathy for the Spanish Republic were mounted, raising funds and seeking to generate political support. Hollywood stars lent their names to the cause, just as writers such as Ernest Hemingway lent their pens and painters, most famously Pablo Picasso, their brushes. Similarly, Ukraine has received its share of celebrity attention, including visits from Sean Penn, Angelina Jolie, Bono, Ben Stiller, and Orlando Bloom. Both causes received extensive and sympathetic media coverage, as the destruction of Mariupol recalled that of Guernica.

However, the parallel between the two conflicts goes beyond the fact that both wars inspired gestures of support from well-known figures. In both cases, foreign volunteers joined the struggle. The International Brigades—with units from Britain, France, the Balkans, and the United States, as well as ones made up of exiles from Germany and Italy—served as shock troops and took heavy casualties.

After the Russian invasion of Ukraine, volunteers from different countries began to appear and were organized into the “International Legion for the Defense of Ukraine.” Of course, there are essential differences between the two cases. The Soviet-run Communist International organized the International Brigades, and many (although by no means all) of those who fought in them were communists. The current-day Ukrainian Legion is politically heterogenous, consisting of individuals who made their way to Ukraine with varying stories—some ideologically committed to aiding an embattled democracy, some remembering the plight of their own countries when they had suffered under Soviet domination, and others adventurers just looking for a new fight.

Testing Weapons for the Next War

Another way Russia’s war against Ukraine resembles the Spanish Civil War is that it has become a proving ground for new weapons and military tactics. In Spain, Germany first used the Junkers JU87 “Stuka” dive bomber in combat, and the Messerschmidt BF109 fighter aircraft later dueled with the Spitfire in the skies over Great Britain. The Soviet Union introduced the T-26 tank used in World War II. It pioneered innovative night-fighting aviation tactics, which it later put to good use after Germany invaded in 1941.

Similarly, the war in Ukraine has seen the introduction of new weapons systems, most notably the extensive use of drone systems. The Anglo-French Storm Shadow/SCALP missile has effectively checkmated Russia’s Black Sea fleet. Russia has employed its Kinzhal hypersonic missile to attack Ukrainian cities and military installations. Both sides have faced unexpected difficulties in using armor to obtain breakthroughs, and armies in future wars may need to rethink their tactics. Whatever the outcome in Ukraine, this war has taught new lessons to generals and admirals worldwide.

When Help Dries Up

The Spanish Republic ultimately failed in its struggle against the German and Italian-backed rebels. The final defeat came at the end of March 1939. Key to this failure was its slow abandonment by its great power patron, the Soviet Union. Although it provided Spain with significant material and technical assistance in the first year of the war, Soviet help progressively tapered off. Some of this may have been because of difficulties in getting aid into Spain, as the Republic lost control of key ports and German and Italian ships attacked cargo vessels seeking to enter those that remained available. Also, France was unwilling to allow overland shipments after a change of government.

Stalin’s strategic calculus also changed. Japan and the USSR clashed in the Far East. German and Italian support for the rebels in Spain remained strong (and the U.S. and the European democracies stayed on the sidelines). Over time, Stalin’s attitude toward Hitler switched from opposition to accommodation, and without ever abandoning his rhetorical support for the Republic, he progressively unwound his commitment to Spain. He engaged in secret negotiations leading to a non-aggression pact with Germany, and only six months after the Republic’s final collapse, both Germany and the Soviet Union were invading Poland and dividing it up between them.

Until recently, Ukraine has enjoyed consistent support from the United States and its NATO allies. However, the question of how long this will continue remains open. And, as of March 2024, Ukraine is losing ground with the funding for U.S. assistance stymied in Congress. And even if aid for the current year is approved, its continuation into 2025 cannot be assured as ever more voices call for a “negotiated” solution while Putin and his regime reiterate their maximalist goals of both retaining seized eastern territories and assuring a pro-Russian government in Kyiv.

Stalin’s decision to abandon Spain may have seemed logical at the time. A few months later, he and Hitler were dividing up Poland together. In less than two years, his erstwhile partner’s tanks were driving towards Moscow. While this trajectory of events can hardly be blamed entirely on what happened in Spain, the abandonment of the Republic was a culmination of failures by those threatened by Nazi Germany that began in the Rhineland and went on to Austria and Czechoslovakia before both Western Europe and the Soviet Union found themselves paying the price of appeasement.

Those who believe that the United States and Europe should liquidate their commitment to Ukraine might do well to remember the fate of the Spanish Republic. It was hardly a perfect state, wracked by internal ideological conflict, any more than Ukraine is, with its ongoing corruption problems. But it is easy enough to read what lessons Hitler and Mussolini took from the Soviet Union’s decision to abandon Spain (not to mention the democracies’ decision not to aid it at all). We can only hope that there will not be an abandonment of Ukraine from which Putin will draw similar conclusions.

Richard M. Sanders is a Senior Fellow in the Western Hemisphere at the Center for the National Interest. A former member of the Senior Foreign Service of the U.S. Department of State, he served at embassies throughout Latin America and Spain. He also served the Department of Defense as Foreign Policy Advisor to the Chief of Staff of the U.S. Army.

Image: Shutterstock.com.