For centuries, military uniforms have been closely tied to citizenship. In much of Europe they still are, but the principle is no longer universal. Some Armed Forces have begun to expand their recruitment pool to citizens of other countries, adopting very different models: opening to citizens of the European Union, access reserved for specific nationalities, residency requirements, or corps specifically designed for foreign personnel.

The French Foreign Legion naturally remains the most famous example, but it is no longer the only one. Within the European Union there are now very different models: Belgium opens widely to citizens of the European Economic Area, Ireland also requires a residency link, Denmark allows foreigners who have a concrete relationship with the country to apply for access to initial military service, Spain selects specific nationalities, and Latvia has even provided a channel for foreign citizens in case of mobilization. Other countries, such as Italy, the Netherlands, and Austria, continue instead to tie military status much more rigidly to national citizenship.

The question is also interesting when looking at Italy. Italian Armed Forces continue today to require Italian citizenship in normal competitions for military personnel. At the same time, the personnel model is evolving and Parliament has worked on expanding staffing levels and creating an Auxiliary State Reserve of up to 10,000 volunteers. In this context, a question that is today purely political and strategic becomes inevitable: in the future will Italy maintain a completely national system or could it consider some of the solutions already adopted by other European countries?

Before arriving at Italy, it is therefore worth understanding what others are already doing.

Belgium: the model most open to European citizens

This is probably the most interesting case for understanding how far a national army can open itself to other European citizens.

Belgian Defence explicitly establishes that to apply as a military member one must be:

Belgian citizens or citizens of a member state of the European Economic Area or the Swiss Confederation.

An Italian, being a citizen of the European Union and therefore of the European Economic Area, is therefore fully among the admitted nationalities.

We are not talking about a special "foreign legion" or a separate unit.

Access concerns the true Belgian Armed Forces.

The official Defence page indicates application possibilities in the categories of:

• soldier or sailor;

• non-commissioned officer;

• officer.

For soldiers and sailors, a diploma is not necessarily required; for non-commissioned officers and officers, educational requirements vary depending on the role. Defence further clarifies that for approximately 99% of its military positions, no previous professional experience is required.

However, there is an important limitation: some specific positions are reserved for Belgian citizens, a circumstance that is indicated in individual calls.

The opening to Europeans also applies to the Belgian military reserve. The page dedicated to reservists uses the same nationality requirement: Belgians, citizens of the European Economic Area, or Swiss.

This means that, at least from a nationality perspective, an Italian can even compete to become a reservist in the Belgian Armed Forces.

Particularly interesting is also the presence among Belgian training options of properly operational military specialties, from infantry to para-commandos, as well as engineering, drones, communications, and numerous technical specializations.

Of course, final admission then depends on passing the selections, medical and physical fitness, language requirements, and the conditions provided for in the individual position.

Ireland: European openness, but tied to residency

Another concrete possibility comes from the Irish Defence Forces.

The official Irish rules indicate among the people who can be enlisted:

• Irish citizens;

• citizens of states belonging to the European Economic Area;

• recognized refugees;

• persons holding certain forms of international protection.

Again, therefore, an Italian citizen meets the nationality requirement.

However, there is a fundamental condition: the candidate must be “ordinarily resident in Ireland”, that is, normally resident in Ireland. It is therefore not enough to live in Italy and simply present yourself at an Irish recruitment center.

For General Service Enlistment, the age currently indicated by the Defence Forces is between 18 years and under 39 years on the date established by the relevant selection procedure.

The possibilities concern the entire Defence Forces system:

Army, Naval Service, and Air Corps.

Here too there is no separate formation for foreigners. Once admitted, the European citizen enters the normal Irish Armed Forces.

La formazione iniziale dei nuovi arruolati dura attualmente 12 settimane, seguita dalla preparazione professionale relativa alla specialità e alla componente scelta.

Il modello irlandese è quindi radicalmente differente da quello della Legione Straniera: non si entra in un corpo costituito appositamente per gli stranieri, ma nelle Defence Forces del Paese alle stesse condizioni generali previste dal sistema di reclutamento.

Danimarca: stranieri ammessi al servizio militare, ma serve un vero legame con il Paese

Anche la Danimarca rappresenta un caso interessante, sebbene diverso da Belgio e Irlanda.

La Difesa danese prevede infatti che un cittadino straniero possa chiedere di partecipare alla værnepligt, il sistema di servizio militare e formazione iniziale danese. Non si tratta però di un'apertura indiscriminata a chiunque viva all'estero.

Tra le condizioni indicate dalla Difesa figurano un valido titolo di soggiorno e lavoro in Danimarca, un legame documentato con il Paese e l'aver richiesto o prevedere di richiedere la cittadinanza danese. È inoltre necessario possedere una conoscenza sufficiente della lingua.

Se le condizioni vengono soddisfatte, il candidato straniero può essere trattato, nella procedura di valutazione per il servizio, alle stesse condizioni previste per i cittadini danesi.

Per un italiano significa quindi che non basta il passaporto UE, ma un cittadino italiano stabilmente residente e integrato in Danimarca può, in determinate condizioni, ottenere l'autorizzazione a svolgere il servizio militare danese.

È un modello importante perché introduce un principio diverso: non la cittadinanza come requisito assoluto, ma il legame concreto e stabile con lo Stato.

Lussemburgo: cittadini UE sì, ma con condizioni più rigide

Il caso del Lussemburgo è più complesso.

La nuova organizzazione dell'Armée luxembourgeoise prevede alcune possibilità di accesso per cittadini dell'Unione Europea.

Un esempio particolarmente interessante riguarda la carriera da ufficiale attraverso il cosiddetto reclutement indirect.

Secondo la pagina ufficiale dell'Esercito lussemburghese, il candidato può essere cittadino lussemburghese oppure cittadino di uno Stato membro dell'Unione Europea, purché abbia la propria residenza abituale nel Granducato e vi abbia soggiornato legalmente per almeno 36 mesi, con l'ultimo anno immediatamente precedente alla candidatura trascorso senza interruzioni nel Paese.

Un cittadino italiano residente da almeno tre anni in Lussemburgo può quindi, in presenza degli altri requisiti, accedere a questa particolare procedura.

La formazione è tutt'altro che simbolica: per questa via gli aspiranti ufficiali seguono quattro anni di formazione universitaria e militare presso l'École Royale Militaire di Bruxelles, seguiti dalle specializzazioni.

Più particolare è la situazione dei soldati volontari.

La pagina ufficiale attualmente richiede la cittadinanza lussemburghese oppure quella di uno Stato UE con il quale il Lussemburgo abbia concluso l'accordo previsto dalla normativa, oltre ad almeno 36 mesi di soggiorno regolare nel Granducato, dei quali l'ultimo anno continuativo. Sono inoltre richieste conoscenze linguistiche nelle lingue amministrative del Paese.

Proprio questo requisito dell'accordo bilaterale rende necessario verificare la posizione della singola nazionalità prima di considerare automaticamente accessibile il percorso da soldato volontario.

La situazione potrebbe peraltro cambiare.

Nel dicembre 2025 il governo lussemburghese ha annunciato una riforma del reclutamento che prevede, tra le altre cose, di consentire in futuro l'arruolamento come soldati volontari anche a cittadini UE non residenti nel Granducato. La stessa comunicazione governativa precisa però che queste modifiche necessitano di interventi legislativi e non possono quindi essere considerate automaticamente già operative.

Spagna: stranieri sì, ma soltanto di determinate nazionalità

La Spagna costituisce un esempio perfetto di quanto sia importante distinguere tra “esercito aperto agli stranieri” ed “esercito aperto ai cittadini europei”.

Le Fuerzas Armadas spagnole arruolano effettivamente cittadini stranieri.

La convocazione 2026 per Tropa y Marinería prevede addirittura che l'organico possa comprendere fino a 7.110 militari non cittadini spagnoli.

Questo però non significa che possa candidarsi qualsiasi straniero.

Il Ministero della Difesa spagnolo ammette cittadini di:

Argentina, Bolivia, Costa Rica, Colombia, Cile, Ecuador, El Salvador, Guatemala, Guinea Equatoriale, Honduras, Messico, Nicaragua, Panama, Paraguay, Perù, Repubblica Dominicana, Uruguay e Venezuela.

L'Italia non compare nell'elenco.

Di conseguenza un cittadino esclusivamente italiano non può sfruttare il canale previsto dalla Spagna per il reclutamento degli stranieri.

Regno Unito: il legame storico con Irlanda e Commonwealth

Situazione simile nel Regno Unito.

Il British Army permette l'accesso ad alcune categorie di cittadini stranieri, ma il sistema non è fondato sulla cittadinanza europea.

According to current rules, British, Irish, and certain categories of Commonwealth citizens may apply. For the Army Reserve there are also specific requirements related to residence or immigration status.

An Italian citizen does not therefore acquire any right to enlist simply because they are Italian or an EU citizen.

The situation naturally changes for those who also possess another admitted second citizenship, for example Irish citizenship.

This is a particularly important distinction also when discussing units such as 21 SAS and 23 SAS, belonging to the UK Special Forces Reserve: the opening to candidates without previous military service does not eliminate the nationality requirements provided for by the British Army.

Netherlands: Dutch citizenship required even for the reserve

The Netherlands, by contrast, maintains a distinctly national approach.

Dutch Defense lists among the general requirements for military employment the possession of Dutch citizenship. The same principle applies to reserve personnel: the official pages dedicated to reservists of the Army, Navy, and Air Force expressly require Dutch nationality.

Dual citizenship is permitted, but one of the two must be that of the Netherlands.

Consequently, a citizen exclusively Italian cannot today apply as a Dutch military member or reservist simply by virtue of European citizenship or residence in the country.

Latvia: foreigners admitted in case of mobilization

Latvia offers yet another and particularly interesting example in the new European strategic context.

In October 2024 the Latvian Parliament approved amendments to military service legislation that allow, in case of mobilization, foreign citizens to voluntarily serve in the Latvian Armed Forces.

The possibility concerns citizens of the European Union, EFTA, and NATO, as well as citizens of Australia, Brazil, New Zealand, and Ukraine, provided they meet the other requirements.

This means that, in a mobilization situation provided for by Latvian law, even an Italian citizen could voluntarily join the Latvian Armed Forces.

It is therefore not a permanent opening of normal recruitment, but a tool designed to rapidly increase the pool of available personnel in a situation of national emergency.

For the Italian debate this is perhaps one of the most interesting models: it demonstrates that between the system completely closed to foreigners and permanent opening there is also a third path, that of extraordinary access linked to mobilization.

Germany: German citizenship as a rule, but exceptions exist

Germany too maintains as a general rule a distinctly national criterion.

The Bundeswehr normally lists among the requirements to become a member the possession of German citizenship. Being a citizen of Italy, France, Belgium, or any other country of the Union is therefore not, in the generality of careers, sufficient to wear the German uniform.

However, there is at least one significant officially declared exception: the Bundeswehr recruitment portal specifies that in the Militärmusikdienst, the military music service, it is possible to be hired even without German citizenship, provided the other requirements are met.

It is a very limited exception, but significant because it demonstrates how even a system strongly tied to citizenship can provide openings for specific professional skills.

France: the separate model of the Foreign Legion

France naturally remains the best-known case thanks to the Légion étrangère, created precisely around the principle of recruiting foreign citizens.

But this is a completely different model compared to Belgium and Ireland.

In the Belgian or Irish case, in fact, the Italian can be admitted directly into the normal national military structures thanks to the recruitment rules provided for EU or EEA citizens.

And it is precisely this difference that shows how there is no single model of openness to foreigners in Europe. Some create a specific corps, some admit certain nationalities, and some consider European citizenship or residence a sufficient requirement to compete alongside national citizens.

Seven different models for the same problem

Putting together these cases reveals a much more interesting picture than the simple question "which army recruits foreigners?".

Belgium uses a substantially European model, opening many positions to citizens of the European Economic Area and Switzerland. Ireland follows a similar logic, but adds the requirement of normal residence in the country. Denmark allows foreigners permanently linked to the country to request access to initial military service. Luxembourg allows some forms of access to EU citizens through residence requirements and specific conditions. Spain chooses instead a selective system based on nationality, aimed especially at countries with strong historical and linguistic ties with Madrid. Latvia opens to foreigners from allied countries in case of mobilization. France, finally, has the most radical and historically consolidated solution: a military corps specifically structured for international recruitment.

Alongside these models there are then countries like the Netherlands, where national citizenship remains necessary even for the reserve, and Germany, which maintains German citizenship as a rule but contemplates extremely limited openings for specific skills.

It is not therefore necessarily a matter of replacing national citizens with foreign personnel. In the various countries the opening serves to broaden the recruitment pool, find personnel and skills and, in some cases, transform people already resident and integrated in the country into a resource also for Defense.

And Italy? Today the requirement remains Italian citizenship

The Italian system is currently much closer to the Dutch one or to the general German rule than to the Belgian one. Normal military recruitment notices continue to indicate among the requirements the possession of Italian citizenship. This is, for example, the case in the 2026 procedures for volunteers of the Armed Forces.

This means that today a French, Spanish, Romanian or Polish citizen who lives stably in Italy, but has not acquired Italian citizenship, cannot simply apply to become a VFI in the Army, Navy or Air Force on the sole basis of EU citizenship or residence.

But the model of the Italian Armed Forces is already undergoing transformation for other reasons. The revision of the military model provided, among the instruments to be developed, an auxiliary State Reserve not exceeding 10,000 units of volunteer personnel, while the debate on the size of personnel, on mobilization capacity and on finding specialized skills has returned central to the new European strategic scenario.

Opening to foreigners is not today the recruitment policy of the Italian Armed Forces, nor should it be presented as an already decided reform. But European examples make it possible to reason about options that, in the future, could enter the debate.

A first hypothesis would be the Belgian model: admit to military competitions citizens of the European Union, possibly excluding particularly sensitive assignments or those linked to national security.

A second possibility could recall the Irish model, limiting access to foreigners who reside stably in Italy for a certain period and thus already have a concrete link with the country.

A third model could recall Denmark, linking access not to simple European citizenship but to residence, integration and a stable link with the country.

A fourth model would be the Spanish one, with the identification of certain nationalities admitted on the basis of historical, strategic or bilateral relations.

There would finally be the Latvian model: keep ordinary recruitment closed, but provide by law for the possibility of welcoming foreign volunteers from allied countries in case of mobilization or serious national emergency.

Finally, one could imagine an extremely selective opening only for hard-to-find skills: cyber, IT, medicine, engineering, languages, maintenance of complex systems and other technological skills. It would be a logic different from simple numerical increase of personnel and closer to the principle that already inspires, in other respects, Italian instruments such as the Selected Reserve, used to find from the civilian world skills not fully available within the Armed Force.

Any eventual choice would naturally require regulatory changes, security checks and a political decision on a particularly sensitive issue: to what extent should military service remain tied to citizenship?

Can an Italian instead serve legally in a foreign army?

Yes, in general terms an Italian citizen can serve in the Armed Forces of a foreign state: in the Italian legal system there is no general prohibition that makes the simple recruitment in a foreign army automatically unlawful.

The central rule is article 12 of law 5 February 1992, n. 91, on citizenship. Paragraph 1 does not establish that entering a foreign army automatically results in loss of Italian citizenship. Loss occurs if the citizen, while serving in the military for a foreign State or holding public employment with a foreign State or public entity or an international organization of which Italy is not a member, fails to comply, within the set deadline, with an injunction from the Italian Government to abandon that service or employment.

In other words: voluntarily enlisting in the Belgian or Irish Armed Forces, for example, does not in itself result in loss of Italian citizenship. For the consequence provided in paragraph 1 to take effect, it is necessary that the Italian Government formally orders the person to leave the service and that he continues to serve despite the order. The Ministry of Foreign Affairs in fact describes the situation as that of a citizen who voluntarily enlists in the army of a foreign State and continues service despite an explicit prohibition from the Italian Government.

Different is the case governed by paragraph 2 of article 12. If Italy is formally at war with a foreign State, the Italian citizen who has accepted or has not abandoned public employment with that State, or has served in its military or has voluntarily acquired its citizenship, loses Italian citizenship at the moment the state of war ceases. This is therefore an exceptional situation linked to a state of war involving Italy, not simply to individual participation in a conflict abroad.

This situation should also be distinguished from possible enlistment or recruitment to participate in armed conflicts outside the normal Armed Forces of a State: in those cases, other Italian and international criminal laws may come into play, depending on the concrete circumstances, the party for which one fights, and the conflict involved.

For the case dealt with in this article, that is, an Italian who submits a regular application for enlistment in the official Armed Forces of Belgium, Ireland, or another State that legally permits such access, the conclusion is therefore simpler: Italian citizenship, as a rule, is not lost and enlistment is not prohibited as such, except for the specific cases provided for by Italian law.

Could the future of military recruitment be less national?

For now Europe is proceeding in a scattered manner. There is no "European labor army" nor an EU rule requiring States to open their Armed Forces to citizens of other Member States. Each government maintains its own approach and views differently the relationship between citizenship, loyalty to the State, and military service.

But the comparison is significant. Belgium demonstrates that it is possible to integrate European citizens directly into regular Armed Forces. Ireland shows that residence can become the real link required with the State. Denmark ties openness to concrete integration in the country. Spain limits access to certain nationalities. Latvia has chosen to allow the contribution of citizens of allied countries in case of mobilization. France continues to use a specifically international corps. The Netherlands and Italy, for now, maintain instead an approach much more tied to national citizenship, while Germany provides at least some specialized exceptions.

For Italy this does not necessarily mean that the path to follow should be that of enlisting foreigners. It does mean, however, that, while the country reconsiders personnel, reserves, mobilization capacity, and skills necessary for 21st-century wars, the pool from which military personnel are recruited could eventually also become part of the discussion.

The question, therefore, is not only whether an Italian today can enlist in Belgium or Ireland. It is broader: ten or twenty years from now, to serve in the Armed Forces of a European country will it still be indispensable to hold its passport?