Following Russia’s invasion, Ukrainian President Volodymyr Zelensky established the International Legion of Territorial Defense of Ukraine. Through this group, it is possible for nationals of any state to enlist in the Ukrainian military against Russian aggression. The Ukrainian Defense Ministry claims some 20,000 foreign nationals from over 50 countries have volunteered to date, including 3,000 American citizens. It is currently unclear how much of an impact the International Legion will have on the war. The legal situation for American volunteers is even less clear. While the United States has expressed support for Ukraine’s struggle, they lack clear policies or laws on foreign military volunteering. Those enlisting may face prosecution under the outdated, convoluted and unevenly enforced laws that do exist.
The US Constitution outlaws treason, defining it as “levying War against (America), or in adhering to (American) Enemies, giving them Aid and Comfort.” Additionally, the Neutrality Act of 1794 prohibits American citizens from waging wars against “any foreign prince or state of whom the United States (is) at peace.” The Act was passed in response to specific circumstances. In 1793 the Ambassador of Revolutionary France, Edmond-Charles Genet, was recruiting Americans to fight in Europe. The Citizen Genet Affair provoked diplomatic outrage, saw the French ambassador expelled and nearly drew the US into war against France’s enemies. The resulting Neutrality Act was specifically intended to outlaw Americans serving in wars overseas in which the US had no official involvement. It has been amended repeatedly since 1794 but remains in force to this day. It was most frequently applied to filibusters, referring to American citizens who independently tried to establish pro-US regimes in South America in the 19th Century. More recently filibusters include Operation Red Dog, the 1981 attempt by American and Canadian neo-Nazis to overthrow the government of Dominica and establish a white supremacist narco-state there. Despite the insanity of this plan and the incredible violence it demanded, those involved received only three years in prison, as stipulated by the original Act. The primary US law on fighting abroad is almost as old as America itself and poorly punishes those engaged in criminal behaviour.
During the Spanish Civil War, 35,000 people from 52 countries volunteered for the Republican side, including at least 2,500 from the US. Upon return American volunteers were not prosecuted despite clearly violating the Neutrality Act, however, they faced extralegal discrimination. During WWII, former volunteers were considered security risks and denied promotions and officer commissions. In the subsequent Cold War and Red Scare, many were backlisted by the House Un-American Activities Committee as communists, experienced police surveillance and wiretaps and faced reduced employment prospects. Stripping them of American citizenship was considered but never carried out. The Americans who volunteered in Spain were never charged with any crime related to foreign military service but nonetheless experienced extra-legal discrimination. Rather than rely on its courts, the American government and society extrajudicially punished these people for being presumed communists.
Since 2014, Daesh received some 30,000 international fighters to their so-called Islamic State, including at least 73 individuals from the United States. Comparatively, at least 173 Americans traveled to Syria and Iraq to join various anti-Deash military forces. Volunteers on both sides of the conflict were primarily ideologically driven, motivated by Daesh’s violent jihadi rhetoric or by opposition to Deash and its horrible crimes. Foreign Daesh volunteers who survived the conflict have been universally prosecuted as terrorists and several Americans have faced prosecution for joining or attempting to join Daesh. Americans who fought against Daesh face a much more complex situation. There were many factions and militias in this conflict which all featured complex politics and splinter factions. Certain anti-Daesh groups are designated as terrorists by the US, US allies, or other states and the list of terrorist organisations is ever evolving and, in some cases, classified information. Anti-Daesh volunteers could unwittingly find themselves in what some states consider a terrorist organisation. The complexity of foreign volunteers against Daesh demonstrates the difficulty of making clear, comprehensive policy on foreign military volunteering. Anti-Daesh veterans face an uncertain future stemming from unclear laws, much like those who fought in Spain.
While it is too early to determine the final number of volunteers in Ukraine, it is clear their motivations are to oppose Vladimir Putin’s unprovoked aggression. Historical precedent indicates individuals who volunteer will face significant challenges - on and off the battlefield. American laws addressing international military volunteers are dated, obscure and selectively enforced. In recent conflicts, prosecution for terrorism is more likely and results in longer prison sentences. The American government claims to fully support Ukraine in its existential struggle against Russia. It must also support the American citizens who have been inspired to join Ukraine and present a clear policy on international military volunteering.