Ukraine Symposium – Russia’s Trial of Australian Oscar Jenkins: Status, Legitimacy, and Lawfare

When Australian national Oscar Jenkins crossed into Ukraine and picked up arms, he likely anticipated danger. What he may not have anticipated was the murky legal theatre into which he’d be thrust. Captured in late 2024 and sentenced to thirteen years of confinement, Jenkins was charged with acting as a mercenary by the self-proclaimed Luhansk People’s Republic (LPR). But behind the political posturing and quasi-legal theatre lie other serious questions under international humanitarian law (IHL) including: who is the detaining power; was Jenkins a mercenary; and was his trial legitimate?

Is the Luhansk Peoples Republic a Detaining Power? Not Quite.

According to Russian media and legal filings, Jenkins’ case has been referred to the “Supreme Court” of the LPR. It appears he was detained and prosecuted by the LPR itself. But appearances in war are rarely the whole story, particularly for the purposes of IHL. And what matters for the purposes of the 1949 Geneva Conventions is who is the detaining power. The answer to this question hinges on identifying who the “parties to the conflict” are, as it is they who bear the primary responsibility in ensuring that the conflict is carried out in accordance with IHL (p. 29). This obligation includes ensuring that individuals who have been captured and detained are treated consistently with the Conventions, whatever their status.

There is no doubt that in 2014 the LPR and Ukraine were parties to a non-international armed conflict (NIAC) in the Donbas region. The confrontations between the LPR and the armed forces of Ukraine easily reached the threshold of “protracted armed violence between governmental armed forces and organised armed groups” which is necessary for the existence of a NIAC (see International Criminal Tribunal for the former Yugoslavia, Prosecutor v. Tadic, para. 70). Had Jenkins been captured by the LPR then, questions about the LPR’s obligations under IHL as a non-State armed group would have been appropriate, including what legal basis there was for detaining him in a NIAC.

But after more than a decade, the situation on the ground has changed significantly. Since at least 2022, there is ample evidence that Russia has exercised, at the very least, overall control over the LPR. Russia has provided not just political or logistical support. It has directed military operations, coordinated governance, and following the unilateral annexation of the region in September 2022, introduced legislation that formally incorporated the LPR’s military structures into its own armed forces.

That process may not be legally complete, but it signals a deepening level of integration, so much so that it can be argued that the acts of the LPR are attributable to Russia under international law, specifically under one of the rules reflected in Article 4, 5, and 8 of the International Law Commission’s Articles on State Responsibility. In any case, Russia’s overall control over the LPR and other non-State groups is enough to “internationalize” the conflict in the Donbas, making Russia the detaining power for the purposes of the Geneva Conventions in the Donbas region.

That designation matters. It means that Russia, not the LPR, bears the full spectrum of legal obligations towards Jenkins under IHL, either as a prisoner of war under the Third Geneva Convention (GC III) or as a civilian under the Fourth Geneva Convention (GC IV). These obligations include humane treatment, judicial guarantees, and protections against coercion and unfair trial. Whether the trial is being conducted in Luhansk or Lipetsk, Russia is on the legal hook.

Some may be tempted to compare Jenkins’ case with that of foreign volunteers captured in Syria or Iraq, where NIACs predominate. In those contexts, captured fighters often fall into a legal grey zone. Prisoner of war status does not apply and IHL provides more limited protections.

But Ukraine is not Syria. As stated above, the conflict between Ukraine and Russia, including Russia’s occupation of parts of Donetsk and Luhansk, is an international armed conflict (IAC). The application of GC III is not discretionary; it is triggered by the existence of an IAC and the detention of a person who arguably meets the prisoner of war criteria. Even if one argues Jenkins is not a lawful combatant, his detention is governed by an IHL regime far more protective than would apply in the NIAC context.

Why does all this matter? Because legal status determines treatment. A prisoner of war cannot be tried for taking part in hostilities, only for war crimes or other legal violations. A civilian must be accorded due process and cannot be punished for participating in hostilities unless lawful grounds exist. A mercenary, even if unprotected under GC III, is not stripped of all protections: minimum guarantees under Article 75 of Additional Protocol I to the Geneva Conventions (AP I) still apply.

What Jenkins is called may be political. But what he is, legally, determines whether his current detention and conviction at trial are lawful or not.

Mercenarism, Mislabelling, and Modern Legal Warfare

Russian authorities and the so-called Supreme Court of the LPR claim that Jenkins fought in Ukraine for personal financial gain and should therefore face criminal responsibility as a mercenary and not benefit from prisoner of war protections. But under international law, the label of “mercenary” is far from simple, and far more consequential than it might appear.

The legal definition of a mercenary is both narrow and specific. Article 47 of AP I sets out a six-part test. A person must:

1. Be specially recruited to fight in an armed conflict;

2. Take direct part in the hostilities;

3. Be motivated essentially by the desire for private gain;

4. Be promised material compensation substantially in excess of that paid to combatants of similar rank;

5. Not be a national of a party to the conflict; and

6. Not be a member of the armed forces of a party to the conflict.

Miss one element, and the classification fails.

Most foreign volunteers fighting for Ukraine—including Jenkins—do not qualify as mercenaries on multiple fronts. If Jenkins was formally integrated into the Ukrainian International Legion or another regular unit, then he was part of the armed forces of a party to the conflict, making the mercenary label legally inapplicable. Even if he was paid, compensation alone does not prove exclusive private motivation. Many regular soldiers are paid, and most foreign volunteers are driven by political or ideological reasons, not mere money. This is why convictions for mercenarism are so rare. The definition is designed to be exclusionary. That makes it a weak basis for prosecution and a strong signal that something else is going on.

The truth is that the term “mercenary” has never been merely descriptive; it has always been loaded. In today’s information battlespace, it is the modern equivalent of “enemy combatant” or “terrorist”; a rhetorical tool used to strip legitimacy from the captured and deny them the protections of IHL. By painting Jenkins as a hired gun, Russian-aligned authorities seek to deny him prisoner of war status, justify criminal prosecution for lawful participation in hostilities, and undercut public sympathy by suggesting he was in it for profit, not principle.

This is a textbook case of lawfare, the strategic use of legal frameworks (or pseudo-legal ones) to achieve military or political objectives. In Jenkins’ case, the aim is deterrence: to discourage other foreign fighters from joining Ukraine’s war effort by creating a legal precedent of harsh punishment.

But international law doesn’t reward States for creative rebranding. Even if Jenkins were lawfully labelled a mercenary, he would still enjoy protection under IHL. Mercenaries are expressly denied prisoner of war status under Article 47 of AP I. But this does not equate to “open season” on their protection. International law recognises that every person in enemy hands is entitled to some form of protection. At minimum, Article 75 of AP I provides a baseline of “fundamental guarantees” including,

– Humane treatment;

– Fair trial rights;

– Freedom from torture, coercion, or outrages on personal dignity;

– A prohibition on passing sentences or carrying out executions without prior judgment by a regularly constituted court.

There’s also a broader legal problem here: IHL doesn’t have a “mercenary detention regime.” That is, there’s no bespoke category under the Geneva Conventions that governs how States may detain and prosecute individuals labelled as mercenaries. In practice, States either treat them as unlawful combatants (denied prisoner of war protections) or civilians, with all the risks and complications that entails.

For now, what matters is this: the law on mercenaries is strict by design, and Jenkins doesn’t meet its requirements. Stripping him of protection by mislabelling him isn’t just inaccurate. It’s a violation of the rules meant to govern war itself.

Courts Without Countries – Lawfare, Legitimacy, and Russia’s Legal Responsibilities

The courtroom that tried and convicted Oscar Jenkins may not legally exist at all. The so-called Supreme Court of the LPR was likely legally unfounded. But even more pressing is the question of where and by whom Jenkins was tried. Behind the façade of separatist legality lies a deeper problem in international law: how States use unrecognised entities to outsource legal responsibility and what happens when those legal processes fall short.

At first glance, Jenkins’ prosecution appears to be the work of a local judiciary. The LPR claims to have legal authority over the territory it controls, complete with courts, prosecutors, and criminal codes. But under international law, the LPR is not a recognised State. It lacks standing in the United Nations, diplomatic recognition by most of the international community, and crucially, the capacity to independently uphold IHL obligations.

This matters because Jenkins is not just a captured fighter; he is a detained person in an international armed conflict. That indisputable fact brings into play the full weight of the Geneva Conventions. Regardless of who physically holds him, IHL assigns legal responsibility to the detaining power, the legal entity that exercises control and must ensure compliance with IHL. As outlined above, there is persuasive evidence that Russia exercises overall control over the LPR. This has been the case since at least 2022, through direct military command, political integration, and legislative alignment. The practical effect is this: even if Jenkins is held in an LPR facility, and even if his trial is styled as an LPR proceeding, Russia is the detaining power under IHL.

The dangers of legal theatre, such as that on display in Jenkins’ case, are not abstract. Trials held in unrecognised courts, without access to legal counsel, international oversight, or compliance with basic procedural norms, can easily become mock trials, designed more for spectacle than justice. When trials are used to project sovereignty rather than to uphold law, they risk violating the fundamental guarantees of IHL and human rights law alike.

By staging a legal process in a forum that lacks legitimacy, Russia can claim legal distance while still reaping strategic advantage: intimidating future volunteers; bolstering separatist claims to sovereignty; and eroding confidence in Ukraine’s ability to protect its supporters. The result is a dangerous hybrid: legal process as propaganda.

The government of Australia has expressed concern for Jenkins’ welfare and is reportedly making diplomatic representations. But those avenues are narrow. Russia is unlikely to grant consular access to a detainee it claims isn’t under its custody, and the LPR, lacking recognition, offers no meaningful diplomatic channel. This legal black hole is precisely why attribution and recognition matter: without them, the protections of international law become far harder to enforce.

Yet, this is not uncharted territory. From the detention of foreign fighters in the Donetsk “People’s Republic” to earlier trials of captured Ukrainians by Russian-aligned tribunals, there is a growing pattern of using unrecognised proxy courts to stage legal proceedings while evading the corresponding legal obligations. Jenkins is simply the latest example.

Concluding Thoughts

Whether Jenkins is a POW or a civilian, his legal status does not vanish because he was tried in a courtroom with a different flag. Under IHL, it is the substance of control—not the symbols of statehood—that determine responsibility. If Russia controls the territory, then Russia bears the duties of the detaining power. It cannot subcontract its IHL obligations to a breakaway province, nor can it legitimise an illegitimate process by pretending it’s merely observing.

In the end, Oscar Jenkins’ case is not just about one Australian caught in the crosshairs of war. It is a test of whether the rules of armed conflict—and the protections they offer—can survive when legal fictions are wielded as weapons.

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Dr Samuel White is the Senior Research Fellow in Peace and Security at the National University of Singapore’s Centre for International Law.

Dr Giacomo Biggio is a Lecturer at the University of Bristol School of Law.

The views expressed are those of the authors, and do not necessarily reflect the official position of the United States Military Academy, Department of the Army, or Department of Defense. 

Articles of War is a forum for professionals to share opinions and cultivate ideas. Articles of War does not screen articles to fit a particular editorial agenda, nor endorse or advocate material that is published. Authorship does not indicate affiliation with Articles of War, the Lieber Institute, or the United States Military Academy West Point.

Photo credit: 24th Mechanized Brigade of the Ukrainian military